Short for, you only die once. Often when people say Yolo, this is a good response because whatever they are saying yolo about could potentially kill them. Should be said with extreme judgement of those saying YOLO
Tom: Heyy Catherine! Want to try some of this coke I got from the dealer down the street?
Catherine: Yeah sure, YOLO!!
Jim: yeah..parttyyy YODO!!
You Only Die Once; a counter-argument to the popularYOLO ("You Only Live Once").
"Bro, I'm going to down this bottle of vodka then go skydiving! YOLO," Brad said.
Later, Mike says, "Did you hear about Brad? He died in a skydiving accident. YODO."