To moisten a joint, blunt, spliff or other hand-rolled cannabis product with saliva before lighting it, to extend its burn time. The term is a play on the act of baptism, except saliva is used instead of water. 

“Does baptizing joints really help them last longer?”

“I was all set to join a smoke circle, when someone baptized the joint—I was like, ‘nah, I’m out.’”

Should I baptize my joints?

Baptizing joints, blunts, or other rolled weed products is a personal choice. If you are going to baptize a joint, it’s usually only done when smoking by yourself or with friends or loved ones. Dispensaries sell pre-rolled joints that are not baptized and do not have any contact with mouths or saliva. 

There is some anecdotal evidence to suggest a joint or blunt will burn slower with saliva and moisture, but no proof exists for the argument. Too much saliva can lead to clogging the joint and rendering it unsmokable.