Recess in pleasant hospital (5)
I believe the answer is:
niche
'recess' is the definition.
('niche' can be a synonym of 'recess')
'in pleasant hospital' is the wordplay.
'in' means one lot of letters goes inside another.
'pleasant' becomes 'nice' ('nice' is associated in meaning with 'pleasant').
'hospital' becomes 'h'.
'nice' going around 'h' is 'NICHE'.
(Other definitions for niche that I've seen before include "good spot!" , "Shallow recess in a wall" , "Particularly well suited position" , "Specialized market" , "Cosy corner?" .)