Badger, one caught in empty netting (3)
I believe the answer is:
nag
'badger' is the definition.
(I've seen this before)
'one caught in empty netting' is the wordplay.
'one' becomes 'a'.
'caught in' means one lot of letters goes inside another.
'empty' says to hollow out the word (remove centre letters).
'netting' with its middle removed is 'ng'.
'a' put inside 'ng' is 'NAG'.
(Other definitions for nag that I've seen before include "Jade" , "Scold; inferior horse" , "Poor horse" , "Old horse or shrewish wife" , "Complain, worry" .)