Def

The word def is Hip Hop Graffiti slang for brilliant.

Its long form meaning is DEFinitive. If something is very definitive in its representation of its genre or classification, it is indeed def.

If something is 'def' then it is classed as being very good. The term originated in New York in the early eighties.

Def Jam records took their name from this term.

In the UK to 'def someone out' is street slang and can also mean to ignore someone or to forget about them.

Def can also be short form for definition.

Def has also become an accepted term in internet slang as a shortened version of "definitely". Most common usage being "Most def"