Someone who stands up for girls on the internet they barely know, hopefully so they can engage in sexually intercourse with them. Usually males. They are douches who can't get none in real life
xxsomegirlxx: Hay guys like my pic?? -posts pic-
dude001: No, not really, your sorta ugly
man12: wow, your pic is a myspace angle
lulzftw009: show us another at a differnet angle, PICS NAO!
WHITEKNIGHT!!: Guyys, leave her alone. She's just a girl on the internet, and your harrasing her. (the lecture will probably go for a couple paragraphs) ...so yeah, don't be so desparate.
dude12: STFU INTERNET WHITE KNIGHT.