Relief provided in calm seas (4)
I believe the answer is:
alms
'relief' is the definition.
(I've seen this before)
'in calm seas' is the wordplay.
'in' says the answer is hidden in the clue.
'ALMS' can be found hidden inside 'calm seas'.
'provided' is the link.
(Other definitions for alms that I've seen before include "help" , "Charity offering" , "Old word for money given to the poor" , "Charitable giving" , "handed over as charity" .)