Not delete (4)
I believe the answer is:
stet
'not delete' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for stet that I've seen before include "Notation meaning as is, thus" , "Let it stand (on proof)" , "Instruction to cancel a deletion" , "Proofreader's mark that the original text should be kept" , "Cancellation of correction" .)