An internet slang term for "pissed me off."
Finds its origins in the video game "Team Fortress 2" where the sniper character class has a secondary weapon called "jarate" which is a mason jar full of (presumably his own) urine. When he throws it, he says "jaaarate!" and if he scores a hit, gains attack bonuses against the unfortunate target.
"Did you see how that woman just cut me off? That really jarateed me off!"