Stops endlessly providing comfort (4)
I believe the answer is:
ease
'comfort' is the definition.
(easing is a kind of comforting)
'stops endlessly' is the wordplay.
'stops' becomes 'eases'.
'endlessly' means to remove the last letter.
'eases' with its last letter taken off is 'EASE'.
'providing' is the link.
(Other definitions for ease that I've seen before include "'Comfort, rest (4)'" , "Relieve or slacken" , "Freedom from hardship" , "Freedom from discomfort or anxiety" , "No trouble" .)