Anchor, for example, returned by parasite (5)
I believe the answer is:
kedge
'anchor' is the definition.
(I've seen this before)
'example returned by parasite' is the wordplay.
'example' becomes 'eg' (short for 'exempli gratia', 'for example' in Latin).
'returned' shows that the letters should be reversed in order.
'by' says to put letters next to each other.
'parasite' becomes 'ked' (ked is a type of parasite affecting sheep).
'eg' written backwards gives 'ge'.
'ge' put after 'ked' is 'KEDGE'.
'for' is the link.
(Other definitions for kedge that I've seen before include "Use hawser" , "Move boat" , "Light anchor" , "Lively" , "Small anchor" .)