A pejorative term for Southerners; a cross between country bumpkin and mongoloid, utilizing the prefix rube and suffix tard. Best used when someone is being an ignorant and stupid Philistine.
Man 1: Spaghetti again? I'm so sick of Mexican food. Hispanics are terrible cooks and terrible people.
Man 2: Spaghetti isn't Mexican, you rubetard. Why do you always have to say something stupid and ignorant like a brain-dead mongoloid?
Someone who uses the programming language Ruby.
Have you seen Josh's crazy shit Cucumber test code? He's a rubetard!