Not a fan of short hill-dweller (3)
I believe the answer is:
ant
'hill-dweller' is the definition.
(I've seen this before)
'not a fan of short' is the wordplay.
'not a fan of' becomes 'anti' (I've seen this in another clue).
'short' means to remove the last letter.
'anti' with its final letter removed is 'ANT'.
(Other definitions for ant that I've seen before include "One more provident than Grasshopper" , "Termite" , "Emmet or pismire" , "that may be a soldier" , "Proverbially hard-working insect" .)