What each of the other four longest answers in this puzzle is

• A slip of the tongue? - no promises
• Trump the jack, e.g.
• "Blushing crow" for "crushing blow."
• Reverend's mistake: lovey-dovey type is married
• Like this good clue, it might have you stuck!
• A slip of the tongue? — no promises (anag)
• Lack of pies, say
• Something said by self-described birdwatcher?

Wikipedia Word definitions in Wikipedia
A spoonerism is an error in speech or deliberate play on words in which corresponding consonants , vowels , or morphemes are switched (see metathesis ) between two words in a phrase. An example is saying "The Lord is a shoving leopard" instead of " The ...