Fish traps, possibly (5)
I believe the answer is:
sprat
'fish' is the definition.
(sprat is a kind of fish)
'traps possibly' is the wordplay.
'possibly' indicates an anagram.
'traps' with letters rearranged gives 'SPRAT'.
(Other definitions for sprat that I've seen before include "Type of herring - small person or thing" , "Small fish, sardine, say" , "Mackerel bait?" , "Parts of a very small fish" , "one on a fat-free diet" .)