A type of male (or female if her testosterone level is high enough) that pleasures in douchebaggery and being a dick. It is a pronoun for the word "asshole" that you can use in public without fear of an elderly woman overhearing you and going into cardiac arrest.
Though the word stems from the lesser known Bruchenian dialect, grassholes now exist in every crevice of society. Even celebrities and presidents are douchebags these days, and the term "grasshole" provides the larger public a politically correct way of calling someone a fucktard.
Kanye West: Yo Taylor, I'm really happy for you and Imma let you finish, but Beyonce had the best music video of all time.
Taylor Swift: (stands on stage, shocked)
Audience at home: Day-um. Kanye is a grasshole!