Pleased with relaxation (4)
I believe the answer is:
ease
'relaxation' is the definition.
(synonyms)
'pleased with' is the wordplay.
'with' says the answer is hidden in the clue.
'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" .)