Adj. Variation and shortening of the word 'fetching'. Used to describe something cool and trendy. General usage by females, teeny-boppers. You can almost hear it replied with "Like, totally!" Coined by the movie 'Mean Girls'.
A replacement for cool. One thought to be coined by Tina Fey's "Mean Girls", it was actually developed in website www.giygas.net which show's by date that fetch was used before the movie had debuted. Sadly, now that is it has hit mainstream it, will die quickly.
The antonym is antifetch.
Adj: Look at that skater pulling that fetch move!
Interjection: Fetch! That was awesome!