When a female rotates in a counter-clockwise motion around a group of four guys and gives them head in a way resembling someone circling the bases after a home run.
"Yo Man, me and my 3 buddies just got the ill grand slam blow job last night from this chick last night; she really circled the bases with authority."

by G-Schwartz September 20, 2007
Get the Grand Slam Blow Job mug.