Knife work unfortunately put Dan in prison (3,3,4)
I believe the answer is:
nip and tuck
'knife work' is the definition.
I don't know anything about this answer so I can't tell whether this works.
'unfortunately put dan in prison' is the wordplay.
'unfortunately' indicates an anagram (a bad or unfortunate spelling).
'in' is an insertion indicator.
'prison' becomes 'nick' (slang).
'put'+'dan'='putdan'
'putdan' with letters rearranged gives 'pandtu'.
'pandtu' put within 'nick' is 'NIP AND TUCK'.
Can you help me to learn more?
(Other definitions for nip and tuck that I've seen before include "operation" , "Very close" , "Inconclusive as to the outcome (race, match, etc)" , "Cosmetic surgery (informal)" , "Dead level - plastic surgery" .)