Bachelor, fairly flabby, like a cartoon colonel? (8)
I believe the answer is:
blimpish
'like a cartoon colonel?' is the definition.
(reference to the character Colonel Blimp)
'bachelor fairly flabby' is the wordplay.
'bachelor' becomes 'b' (abbreviation e.g. BA=Bachelor of Arts).
'fairly flabby' becomes 'limpish'.
'b'+'limpish'='BLIMPISH'
(Other definitions for blimpish that I've seen before include "reactionary" , "(0f a elderly person) with incurably pompous and conservative views" .)