Girl returns with small hound (6)
I believe the answer is:
harass
'hound' is the definition.
(I've seen this before)
'girl returns with small' is the wordplay.
'girl' becomes 'sarah' (**).
'returns' shows that the letters should be reversed in order.
'with' means one lot of letters goes inside another.
'small' becomes 's' (abbreviation - e.g. clothes size).
'sarah' backwards is 'haras'.
'haras' placed around 's' is 'HARASS'.
(Other definitions for harass that I've seen before include "Trouble or annoy continuously" , "Trouble constantly" , "Continually torment" , "Bother and annoy continuously" , "Repeatedly torment" .)