Embarrassed about fatigue in bed? (7)
I believe the answer is:
retired
'in bed?' is the definition.
(I've seen this before)
'embarrassed about fatigue' is the wordplay.
'embarrassed' becomes 'red' (someone may blush or go red when embarrassed).
'about' is an insertion indicator.
'fatigue' becomes 'tire' (synonyms).
'red' enclosing 'tire' is 'RETIRED'.
(Other definitions for retired that I've seen before include "retreated" , "Pensioned off" , "out of office?" , "Finished work" , "In bed, withdrew" .)