An onliner is someone who plays CS online and does things which are normally impossible to do on LAN. For example an onliner may HS you while on a ladder or while in mid air. These acts are usually met with agression from players who recieve such ridiculous HS's and thus the term onliner was born.

v. collectively or individually finding someone/something to blame for a problem, as opposed to brainstorming which connotes finding solutions to a problem

n. the act of finding someone/something to blame for a problem

(from a TV ad for HD television)

A phrase used by insecure Counter-Strike players to insult other players who don't compete on LAN after getting owned by some dude who is probably better than him

An onliner is someone who

suck a dick.