What does noggin mean

Most commonly, it’s an informal word for “head” and sometimes through metonymy for “brain.”

It's a playful term for the head. I'll sometimes hear it used specifically to refer to the brain, like "what's going on in that noggin of yours?"

"Noggin" is a colloquial term for a persons head, " he got knocked on the noggin."

I like to use it for babies, "what a big noggin!" And, "support that noggin" etc. because it's cute.

'Noggin' also refers the the short horizontal timber bits between vertical studs in timber framed construction. Some folk call them 'dwangs' or 'noggings'.

As your question has already been answered, here's another word meaning head which can be used in a similar fashion: bonce

Head/brain

It's also a wooden brace between two wall studs.

In certain parts of Ireland and Scotland, it means a small cup, like za shot glass. But mostly it means your head.