Exclude most of domestic fowl (6)
I believe the answer is:
bantam
'fowl' is the definition.
(bantam is a kind of fowl)
'exclude most of domestic' is the wordplay.
'exclude' becomes 'ban' (I've seen this in other clues).
'most of' means to remove the last letter.
'domestic' becomes 'tame' ('tame' can be similar in meaning to 'domestic').
'tame' with its final letter taken away is 'tam'.
'ban'+'tam'='BANTAM'
(Other definitions for bantam that I've seen before include "Domestic fowl; small fighter" , "Diminutive breed of hen" , "Supplier of eggs" , "Very small - batman (anag)" , "Small chicken and light boxer" .)