They are caught in steel snares
I believe the answer is:
eels
'they' is the definition.
Both the definition and answer are plural nouns.
Perhaps you can see a link between them that I don't see?
'caught in steel snares' is the wordplay.
'caught in' says the answer is hidden in the clue.
'EELS' is hidden within 'steel snares'.
'are' is the link.
Can you help me to learn more?
(Other definitions for eels that I've seen before include "Conger --; jellied --" , "Slender fishes" , "They swim" , "Slithery fish" , "Odd fish found in the lees" .)