Loathsome chap dragged by the ear (4)
I believe the answer is:
toad
'loathsome chap' is the definition.
(toad can mean an unpleasant person)
'dragged by the ear' is the wordplay.
'dragged' becomes 'towed' (towing is a kind of dragging).
'by the ear' indicates a 'sounds like' (homophone) clue.
'towed' is a homophone of 'TOAD'.
(Other definitions for toad that I've seen before include "species of amphibian" , "Tailless amphibian" , "Contemptible person" , "Wind in Willows hall-owner" , "Small amphibian" .)