Republican took in large mustelid (5)
I believe the answer is:
ratel
'mustelid' is the definition.
(ratel is a kind of mustelid)
'republican took in large' is the wordplay.
'republican' becomes 'r' (abbreviation).
'took in' becomes 'ate' ('eat' can be a synonym of 'take in').
'large' becomes 'l'.
'r'+'ate'+'l'='RATEL'
(Other definitions for ratel that I've seen before include "one wanting honey" , "Honey-badger" , "Honey badger" , "predator" , "Animal of Africa and India - alert (anag)" .)