Bogart is a slang term associated with holding on to a shared joint or pipe of marijuana longer than you should while smoking with friends instead of passing it around.
“Don’t Bogart the joint!”
“Hey, Bogart, pass the joint!”
It means hogging the joint for yourself instead of sharing. The term comes from the actor Humphrey Bogart who often kept a cigarette dangling out of the corner of his mouth. While the term refers to holding onto marijuana instead of sharing among your cannabis friends, it can also be applied to any situation where someone is keeping something all for themselves instead of sharing.