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1 definition by C. U. Farley

(verb): To insert one's head into a sex partner's anus, as if wearing them like a helmet. Requires surgical removal of the receiver's sphincter.
Bob was not happy to learn he would have to wear adult diapers for the rest of his life following the procedure that would allow Janice to helmet him.
by C. U. Farley May 22, 2008