To blow a raspberry with your lips pressed against someone else's skin -- typically her stomach. The intention is to cause ticklish squirming.
(Not my word, I believe this one has entered the vernacular but I noticed that it wasn't in your dictionary yet.) (ED. This may be a variation of The Cosby Show's "zerbert" -- pronounced "zrrbrrt.")
"Her zerbit was so forceful, I laughed so hard that I couldn't breathe."
"He seemed unusually depressed but a good zerbit cheered him up instantly."