Hours in pleasant alcove (5)
I believe the answer is:
niche
'alcove' is the definition.
(I've seen this before)
'hours in pleasant' is the wordplay.
'hours' becomes 'h'.
'in' means one lot of letters goes inside another.
'pleasant' becomes 'nice' (similar in meaning).
'h' placed inside 'nice' is 'NICHE'.
(Other definitions for niche that I've seen before include "Suitable position (in market, life etc)" , "Place that's cosy" , "Recess - suitable position" , "Suitable spot" , "Select place in market" .)