"Blushing crow" for "crushing blow."

• Comical transposition
• What each of the other four longest answers in this puzzle is
• A slip of the tongue? — no promises (anag)
• Something said by self-described birdwatcher?
• No promises to be broken? It sounds the wrong way round
• Like this good clue, it might have you stuck!
• ''Let me sew you to your sheet,'' e.g
• Hated the book, perhaps

WordNet Word definitions in WordNet
n. transposition of initial consonants in a pair of words

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1900, but according to OED in use at Oxford as early as 1885, involuntary transposition of sounds in two or more words (such as "shoving leopard" for "loving shepherd," "half-warmed fish" for "half-formed wish," "beery work speaking to empty wenches," etc.), ...