A person, mainly male, that thinks they're hot shit. People use this term as an insult to said person in order to make fun of their stupidity.
1. Did you see that guy running around the track with his shirt off earlier? Dude is flabby as hell, but he thought he looked like a Greek god. Total hosscakes.
2. Person 1: I can bench 115 on a good day. I know, I know, major props.
Person 2: Ohhhh, nice work hosscakes, nice work.