(verb): a person who stares longingly at people who are eating in the hopes that they will give them some food. (someone in the act of groaking)

(verb): A person who stares at others eating, in the hopes that they will get some food out of it. ( a person who groaks)

(noun): Someone who hangs around a fan community for a thing just to talk about everything they hate about that thing, its creators, its plots, its characters, and its fans.