It's in poor taste to let it stand (4)
I believe the answer is:
stet
'let it stand' is the definition.
(I've seen this before)
'it's in poor taste to' is the wordplay.
'it's in' indicates the answer is hidden within the clue.
'STET' can be found hidden inside 'poor taste to'.
(Other definitions for stet that I've seen before include "Editing instruction that matter marked for deletion is to be retained" , "Ignore instruction to change" , "indicates second thoughts are not always better" , "Proofreader's mark that the original text should be kept" , "(On proofs) instruction to cancel a correction" .)