40k

A insult used in competitive games as a way to relate their skills to someone, who, stereotypically isn't good at video games.

XxxcoolguyxxX: that was terrible...
Gamerdad123: We did our best.
XxxcoolguyxxX: Shut up 40k, I bet you have a family that loves you and a stable mental health

40k

A person that has failed at life. They work a low income job and have no ambition to do better.

That dude is a 40k. He drives a forklift and makes $20/hour.