めっちゃ

very; extremely

Word type: 

Standard: 

すごく

Standard kanji: 

凄く

Example: 

この本、めっちゃおもろいで。読んでみぃ。
This book is really good. You should read it.

Commentary: 

This short phrasing is more common among young people.
Also see めちゃ and めちゃめちゃ.