Hold back from relaxation, then shower (8)
I believe the answer is:
restrain
'hold back' is the definition.
('restrain' can be a synonym of 'hold back')
'relaxation then shower' is the wordplay.
'relaxation' becomes 'rest' ('rest' can be a synonym of 'relaxation').
'then' is a charade indicator (letters next to each other).
'shower' becomes 'rain' ('rain shower' can be a synonym of 'shower').
'rest'+'rain'='RESTRAIN'
'from' is the link.
(Other definitions for restrain that I've seen before include "Stop" , "Prevent (from excess)" , "Tie up - arrest" , "Keep in check" , "Limit" .)