Attack from sheep in one's compound (3,4)
I believe the answer is:
set upon
'attack' is the definition.
(setting upon is a kind of attacking)
'sheep in one's compound' is the wordplay.
'sheep' becomes 'tup' (tup is a kind of sheep**).
'in' means one lot of letters goes inside another.
'compound' indicates anagramming the letters.
'ones' with letters rearranged gives 'seon'.
'tup' put within 'seon' is 'SET UPON'.
'from' is the link.
(Other definitions for set upon that I've seen before include "Attack" , "Mug" , "Attacked" , "Determined to do (something)" .)