Netting wrapped round knight's weapon (5)
I believe the answer is:
lance
'weapon' is the definition.
(I know that lance is a type of weapon)
'netting wrapped round knight's' is the wordplay.
'netting' becomes 'lace' (I've seen this in another clue).
'wrapped round' means one lot of letters goes inside another.
'knight' becomes 'n' (chess abbreviation).
'lace' placed around 'n' is 'LANCE'.
(Other definitions for lance that I've seen before include "Spear carried by mounted soldier" , "fish" , "Spear for a horse-soldier" , "Horseman's long weapon" , "Knightly weapon" .)