Let it stand the test, perhaps (4)
I believe the answer is:
stet
'let it stand' is the definition.
(I've seen this before)
'the test perhaps' is the wordplay.
'perhaps' indicates an anagram.
'test' is an anagram of 'STET'.
(Other definitions for stet that I've seen before include "'In printing, cancel a correction and leave it as it was (4)'" , "Instruction to keep" , "Cancellation of correction" , "cancel amendment" , "'Let it stand, in printing (4)'" .)