Trained surgeons will accept credit for parasites (10)

'parasites' is the definition.
(a scrounger lives off other people)

'trained surgeons will accept credit' is the wordplay.
'trained' indicates anagramming the letters (to train can mean to grow something into a shape).
'will accept' means one lot of letters goes inside another.
'credit' becomes 'cr'.
'surgeons' anagrammed gives 'soungers'.
'soungers' placed around 'cr' is 'SCROUNGERS'.

'for' is the link.