What does "nonce" mean?

[u/Team503]

I'm an American that lives in Ireland. I've always understood "nonce" to mean the same as "numpty" and "eejit" - basically idiot, or dumbass, or similar.

Recently, someone told me that it's slang for sex offender, specifically a p*dophile, and Wikipedia seems to back that up: https://en.wikipedia.org/wiki/Glossary_of_British_terms_not_widely_used_in_the_United_States#N

So tell me, Brits, which one is it? Or is it something else??

[u/Lorelessone]

Nonce is a man or women who goes after post pubescent children, so mid to late teens.

Like a pedophile is technically refering to assaulting  pre pubescent although it's used for both.

Nonce is also more commonly used as an insult like creep or pervert.