Garment left poor Colin hot (9)
I believe the answer is:
loincloth
'garment' is the definition.
(loincloth is a kind of garment)
'left poor colin hot' is the wordplay.
'left' becomes 'l' (common abbreviation).
'poor' is an anagram indicator.
'colin'+'hot'='colinhot'
'colinhot' anagrammed gives 'oincloth'.
'l'+'oincloth'='LOINCLOTH'
(Other definitions for loincloth that I've seen before include "scanty garment" , "this is placed round middle of groin?" , "Minimal garment" , "Garment Indian may have" , "Minimum clothing?" .)