Commonly Used Language on AoPS
Here is a list of commonly used forum language on AoPS.
Bump
"Bumping" means to post on a thread simply to make the thread go back to the top of a forum. Usually on such posts, AoPSers write things like "bumping" or "bump" in the post content.
Troll
Trolling is bad.
Snipe
Sniping is the action of posting to a thread right before another user posted, usually when both posts contain the same content or gist. AoPSers tend to edit their post and add things like "EDIT: sniped!" at the end to signify this.