What’s used for draught in county hospital or site left empty (5,5)
I believe the answer is:
shire horse
'what's used for draught' is the definition.
(a draught horse draws or pulls things along)
'county hospital or site left empty' is the wordplay.
'county' becomes 'shire' (I've seen this before).
'hospital' becomes 'h' (abbreviation for hospital on maps).
'left empty' means to remove the middle letters (the word is emptied out).
'site' with its centre removed is 'se'.
'shire'+'h'+'or'+'se'='SHIRE-HORSE'
'in' acts as a link.
(Other definitions for shire horse that I've seen before include "One good at drawing" , "Strong draught animal" , "Powerful breed of working animal" , "Large draught animal" .)