Work schedule covers old boss of coop? (7)
I believe the answer is:
rooster
'boss of coop?' is the definition.
(as in a chicken coop)
'work schedule covers old' is the wordplay.
'work schedule' becomes 'roster'.
'covers' indicates putting letters inside.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'roster' going around 'o' is 'ROOSTER'.
(Other definitions for rooster that I've seen before include "Adult male chicken" , "Crowing bird" , "Chanticleer" , "Male domestic fowl in USA" , "So retro (anag.)" .)