Tailless leporid, donkey and badger (6)
I believe the answer is:
harass
'badger' is the definition.
('harass' can be a synonym of 'badger')
'tailless leporid donkey' is the wordplay.
'tailless' means to remove the last letter.
'leporid' becomes 'hare' (hare is a kind of leporid).
'donkey' becomes 'ass' (I've seen this before).
'hare' with its final letter removed is 'har'.
'har'+'ass'='HARASS'
'and' acts as a link.
(Other definitions for harass that I've seen before include "Bother and annoy continuously" , "hound" , "Trouble or annoy continuously" , "Badger, annoy persistently" , "Annoy or badger constantly" .)