Pleased with relaxation (4)
I believe the answer is:
ease
'relaxation' is the definition.
(synonyms)
'pleased with' is the wordplay.
'with' indicates a hidden word.
'EASE' is hidden within 'pleased'.
(Other definitions for ease that I've seen before include "Soothe" , "Absence of effort" , "Become less severe; facilitate" , "Comfort; facility" , "Make less severe, comfort" .)