TBS: Tight Bum Syndrome: the action at which some one, who is nervous, clenches their butt cheeks in anticipation of a specific anxiety/nerve inducing event. -Walking is sometimes difficult, although it does make your ass look out of this world.

ITBS: Itchy Tight Bum Syndrome: The occasional time during TBS: Tight Bum Syndrome, when your ass gets extremely. annoyingly itchy. Usually an itch that just doesn't feel right scratching on your own, so you must employ a friend to do it immediately. Or some kind of utensil.
Todd:"Hey Bob, have you ever had a case of ITBS?"

Bob: "I don't think I have Todd, only TBS, what is ITBS?"

Todd: ITBS: Itchy Tight Bum Syndrome, when your ass cheeks are in the position of TBS, but then get extremely itchy all of a sudden. I just can't seem to scratch it properly."

Bob:"Do you need a butt scratcher?"
by canadiangirl237 November 15, 2011
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