look up any word, like cleveland steamer:
 
1.
To talk/sing to one's self
He had a lonely time at lunch today. Yeah, he was just cliffing...
by Nerderific September 13, 2012
 
2.
The process before falling in love with someone, once you have cliffed, you are falling in love with that person. (After you jump off a cliff, you are falling)
Girl A, "Wow! Josh is so cute! I think I'm cliffing."
Girl B, "I know! But Jessica already cliffed for him"
by Violet Meadus May 13, 2013
 
3.
Vomiting; throwing up; hurling; puking etc. etc.

More specifically: Throwing up in someone's car.

Background: After eating McDonald's, Cliff threw up all over Max's car, therefore throwing up in someone's car became "cliffing" and then it became a general term for vomiting.
After eating some suspect curry and smoking too much pot, Zak ended up cliffing all over the back of our van.
by madamemetal013 June 23, 2011