Answer: spoonerisms

AnswerCrossword Clue
SPOONERISMSTranspositions like "It is kisstomary to cuss the bride"
spoonerismsSPOONERISM, a transposition of initial sounds of spoken words, eg 'shoving leopard' for 'loving shepherd'
spoonerismsA verbal error in which a speaker accidentally transposes the initial sounds or letters of two or more words, often to humorous effect, as in the sentence you have hissed the mystery lectures, accidentally spoken instead of the intended sentence you have missed the history lectures