Editor's "don't change" (4)
I believe the answer is:
stet
'editor's don't change' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for stet that I've seen before include "Thus, leave spelling unchanged" , "Eg, molar" , "Retainer" , "(On proofs) instruction to cancel a correction" , "marginal instruction" .)