A "reverse motorboat". Achieved by burying one's face between a supple set of buttcheeks and rapidly shaking the head from side to side. Optionally, one may purse the lips and blow out while botormoating to emulate the sound made by a motorboat's engine.
Johnny's girlfriend didn't have much of a chest, so he flipped her over and botormoated her.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.