A term used in response to anything said, by self or another person, which could be interpreted as sexual in nature. Its origin, which predates the British deodorant commercials, comes from the Halo-based series Red vs Blue, in which the character Tucker uses the term ad infinitum.
In Red vs Blue:

Texas: Lets go get this big thing.

Tucker: Bomchickabowow!
by Haggus71 July 19, 2009
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