Stop open, abnormal delay (8)
I believe the answer is:
postpone
'delay' is the definition.
(postponing is a kind of delaying)
'stop open abnormal' is the wordplay.
'abnormal' indicates anagramming the letters.
'stop'+'open'='stopopen'
'stopopen' is an anagram of 'POSTPONE'.
(Other definitions for postpone that I've seen before include "Put off until future date" , "'Put off, delay (8)'" , "'Hold over, defer (8)'" , "pigeon-hole" , "Put off till later" .)