Comfort stop about to be dropped (4)
I believe the answer is:
ease
'comfort' is the definition.
(easing is a kind of comforting)
'stop about to be dropped' is the wordplay.
'stop' becomes 'cease' (synonyms).
'about' becomes 'c' (abbreviation for 'circa').
'to be dropped' indicates named letters should be taken away.
'cease' with 'c' taken away is 'EASE'.
(Other definitions for ease that I've seen before include "Calm" , "composure" , "Allay" , "Absence of effort" , "Loosen - relax" .)