spoonerism n.

"act or habit of misapplying words through ambition to use fine language," also a word so misapplied, 1826, from Mrs. Malaprop, character in Sheridan's play "The Rivals" (1775), noted for her ridiculous misuse of large words (such as contagious countries for contiguous countries), her name coined from malapropos.

When Mrs. Malaprop, in Sheridan's Rivals, is said to 'deck her dull chat with hard words which she don't understand,' she protests, 'Sure, if I reprehend anything in this world it is the use of my oracular tongue, & a nice derangement of epitaphs'—having vague memories of apprehend, vernacular, arrangement, & epithets. She is now the matron saint of those who go wordfowling with a blunderbuss. [Fowler]

"A deformed language in which the initial consonants of contiguous words are transposed" [OED], 1863, said to derive from the proper name of a Polish count. Compare spoonerism, which describes the same thing.

MARROWSKYING, subs. (general).—At the London University they had a way of disguising English (described by Albert Smith, in Mr. Ledbury, 1848, as the 'Gower-street dialect'), which consisted in transposing the initials of words; as 'poke a smipe' = smoke a pipe; 'flutter-by' = butterfly; 'stint of pout' = pint of stout; etc. This is often termed MARROWSKYING. [Farmer and Henley, "Slang and Its Analogues," 1896]