A highly desirable rock song.
This word was created by a member of Simga Alpha Mu fraternity of San Diego, CA in response to there not being a rock music equivalent to the word slaps.
"Hey man, I've got some new knocks we can rock out to."
"Excuse me, sir. I need you to put on some old school knocks like Lynyrd Skynyrd I can proceed to get incoherently smashed to."
Knocks is another word for titties.
You really do have big knocks, don't you?