A spoonerism is an occurrence in speech in which corresponding consonants, vowels, or morphemes are switched (see metathesis) between two words in a phrase. These are named after the Oxford don and ordained minister William Archibald Spooner, who reputedly did this. They were already in use by the 16th century by the author François Rabelais and called contrepèteries. In his novel Pantagruel, he wrote "femme folle à la messe et femme molle à la fesse" ("insane woman at mass, woman with flabby buttocks"). An example is saying "The Lord is a shoving leopard" instead of "The Lord is a loving shepherd" or "runny babbit" instead of "bunny rabbit." While spoonerisms are commonly heard as slips of the tongue, they can also be used intentionally as a play on words. Source: Wikipedia (en)