Is the word "men" here a common slang to say instead of "guys"? Do native speakers say that?

A boss might address his underlings as "men." You usually see it in the military when a leader is addressing his troops. Doing it elsewhere is probably a reference to the military to intentionally sound very masculine, but it sounds awkward and weird to my native ear. I'm not sure if it's actually used in the military or if you just see it in movies. There are some famous old speeches from generals and stuff that begin with a gruff old general like Patton saying "Men, ..."

The book was written in 1991 and takes place in the 1980s. I believe this may have been a more common way to address a group of male colleagues or acquaintances at that time. “Hello Men” sounds slightly more formal that “Hi guys.”

It’s not slang; rather, it sounds a bit dated and formal, but it still sees occasional use. You often hear it in historical contexts where a superior is addressing a group of workers, soldiers, or other subordinates. Nowadays, when most professional contexts also include women, it’s not super appropriate.

no its uncommon and comes across quite stiff

It's not common, but I think for this book/character, it makes a lot of sense.

"Hello, men" is an odd way to address men. If I'm giving a speech in front of a group that is all men, I'll say "Good morning/afternoon, gentlemen". "Hello, gentlemen" would also work. It's typical to address a group of men as *gentlemen* and not just *men*. More informally, you can say "Hey guys". *Guys* in this case, and generally, is not gender-specific. Women can say "you guys" when referring to a group of women. But the statement "They are guys." means they are men. If it sounds confusing, it's because it is! Funny story: I once got myself in a little trouble when I gave a lecture to a group of small group of med students (I'm a medical doctor). They all happened to be women. I said "Good afternoon, ladies" and somebody took offense to it. Of course, if it were a group of men I'd say *gentlemen* and if it were mixed then I'd say *ladies and gentlemen*. (And it is convention to say *ladies* before *gentlemen*. Nobody says *gentlemen and ladies*.)

It can be common in the context military or police, but not casually.

I find the use of "men" quite strange here and would not use it as it is used here.

Sounds like a boss talking to his workers/subordinates, especially physical laborers or soldiers or ship crew. You wouldn’t really say this normally though. It also sounds a bit old-fashioned to me.

am a woman.   individually and in casual speech, if someone used "man" as a sort of mild exclamation while addressing me, I don't think I'd mind.   things like "oh man, why would you want to do that".  it's a bit 1960's, but then so am I.   if I was part of a group and someone addressed us all as "guys" I'm personally fine with that.  I do it too.  if they addressed us as "men" I'd side eye.  that's militaristic jargon.  

Our teachers used to address us as men in secondary school.

A comanding officer would say this to his men but that doesnt look like the context here. Seems kind of awkward

I must be in the minority, but i use men and boys to address groups of men and friends. It's used in jest but sounds ok.

"Hello, men" is something a boss says to underlings, and in really toxic environments can refer to both men and women (though I don't think any woman would put up with it these days), but mostly for all male audiences of underlings. It's not polite ("gentlemen") but it's not super condescending, I'd say it's informal but outlining a clear hierarchy where the speaker has some authority over the audience. "Hey guys" is generic and non-gender specific even though the origin of "guy" is male-centered (and can still be used as male: "He's a really good guy.") Similar usages for words like "dude" exist, and I've even seen some young Gen Z women using "bro" among themselves as well.

No it's unusual, I would only expect someone to do that if they were making a point about being men and somehow manly 

This is very specifically a preppy thing in this case - rich, elite-school educated snooty white guys from families with money. They would have worn jackets and ties beginning in elementary school and gone to fancy places like Andover and Exeter and then on to Harvard, Yale, Princeton. And their teachers and school deans and so on would have called them *gentlemen,* and *men,* and instilled a certain style of thinking about themselves as superior to..basically everyone. And they would adress each other this way in their private clubs and then at their high status jobs, only slightly ironically. This tone, and references to that social milieu, are present throughout the book (also the related novel The Rules of Attraction, where Patrick Bateman’s brother is a main character.)

It has a military vibe. I wouldn't use it unless you want to sound like an army General. I think I've used it as a joke when my friends and I have had to complete some task, for example.

It's a way to refer to people under your command, usually in a military setting when an officer is addressing the troops.

It's not slang, it's just normal.

sounds a bit dated and formal. Definitely wouldn't call it slang.

American Psycho is set during the 1980s, and it's a highly stylized satire on hyper-masculine corporate culture. I think the use of "Hello, men," here is meant as a joking expression of the hypermasculinity of the character saying it. He's addressing his co-workers like military comrades. It's not something that a real person would say in that situation, except as a joke.

The rest of the text seems stilted too, although not a lot of it to judge from.

Folks or people

I say gentlemen, even casually. I respect my male friends. "What's up gentlemen?"

There is a lot of purposefully unnatural stuff in American Psycho. I didn't recall any of the names or see your full text, but the sentence noting the sunglasses and briefcase brand triggered an immediate "is this American Psycho?" Reaction. Likely as others point out, the idiom is one conveying masculinity since it really feels like something you could say as a military commander talking to your troops, not natural language use like 'guys" would be.

Depends on the situation as well, if this group were friends, then it could have been in jest.

Not really It sounds military. If someone addressed a large group of people this way I would also assume they were at least slightly sexist if it was outside of a military context. “Guys” feels more gender neutral, though I could see some people taking issue with it. I would also call people of any gender “dude”

It’s a bit antiquated and it’s the kind of thing a squadron leader tells his all male crew. It’s not a normal greeting between equals.

I've said this in a deliberately husky voice as a joke, it gives an air of ostentatiousness or professionalism, like "we're here to get a job done". for use at a general get together, other than a joke, I would consider it very strange, but likely not quite remarkable unless it happened a few times.

"Men" isn't slang, it's the literal word for male humans. "Guys" is closer to slang, especially because "hey guys" is often used in a gender neutral fashion. In the US at least, it's not currently common to directly address people as just "men." As another speaker already pointed out, it's more common to say "gentlemen."

It's a very military sort of address, to say 'Hello Men'. Interestingly, 'Hello gentlemen' or 'Hello gents' would read (imo) as a corporate style of address.

"Hey man" is common, I use it, not necessarily only with men either, it's aimed at a singular person though. "Hey men" is not, it's weird and probably deliberate. "Hey guys" is what a informal address to a group of guys (and maybe girls depends who you ask, presume no) should be.

no

Now that the question has been answered, can we talk about the text itself? I haven’t read much literature in English, but the highlighted bit looks just awful to me. Unless this is a deliberate stylistic stunt I can’t grasp due to lack of context, of course. And this isn’t some Wattpad writing, this actually got published in form of a physical book? “Owen says and he introduces”? “Trent Moore and someone named Paul Denton”? Please don’t tell me those sound natural and not tongue-tied to you.

I’m a native English speaker and while I wouldn’t say “men” I would and have addressed a group as “gentlemen” I’m not quite sure as to why.

Honestly the only place it doesn’t seem out of place to the ear would be if there was a clear division of sexes. Like bathrooms or locker rooms. “The men would like this and the women would like this…” It was all the rage in 60’s military movies but no one actually talks like that.

This book should not be used for learning or studying English in any way. Even just this small excerpt is atrocious with its grammar. This needed to be said, so I said it.

Being more respectful you'd probably say gentlemen for colleagues or acquaintances. Men, in my opinion, implies some sort of authority over people.

I've only heard of this in a military setting when addressing troops

It isn't slang. "Men" used in this way is a common and formal way for a commander or leader to address their subordinates, especially in a military setting, but it commonly gets used playfully in less formal settings, such as a boss at a company addressing his employees.

only in military settings or people trying to sound like soldiers. 'men' is commonly used by officers and commanders to refer to the soldiers they lead.

This type of greeting is a little antiquated and tends to be traditionally characteristic of a man greeting his subordinates in traditionally masculine careers such as a lieutenant to his unit, a fire chief to his crew, etc. It's a bit old school when used as a serious greeting but modernly it is sometimes used lightheardly so as to play upon its traditional seriousness. Due to its distinctive traditional association with masculinity, guys will sometimes jokingly address their friends in this way.

No not at all.

To the average person this sounds quite strange. Referring to a group as “men” has quite a military connotation to me. If I was watching a war film and someone said “men, move out” that would sound normal. To say ‘men’ like this in a casual conversation is strange, although some things that are intentionally strange can be endearing or be used in writing to help characterise people. I haven’t read the book so I can’t really speak to the intended effect the word has in this sentence. I just thought I’d offer some more context around using the word to refer to a group.

The basic answer is that it's not common and it's awkward. There's more to be said here but it would probably enter into spoilers and, if you're enjoying the book, it's better not to know much about it going in, IMO. But it is really about satirising a whole group of Yuppies and awful guys in general so having someone be a bit awkward is part of we, as the reader, learning to not like them. Feel free to come back here after you've finished and I can go back over! :D

I honestly don't see anything notable or unusual here. It's like saying "hello, ladies" to a group of women. Apparently some people find this odd, but I'm pretty sure I've done the same thing myself many times.

maybe in the military or meant as purposely overly serious in casual convo.

It's not slang. It's just a way of addressing a group of men.

You would not normally address a group of men in this way. "Guys" would be much more common. I think based on the source material and the description, I'd say the character is gay and his use of "hello, men" is just gay affectation in speech.