"Don't delete this" (4)
I believe the answer is:
stet
'don't delete this' 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 "Direction in printing to cancel a correction or deletion" , "Print as is, don't alter spelling" , "Cancellation of correction" , "It may stand" , "As written, don't change" .)