Amphibian wife found in trap (4)
I believe the answer is:
newt
'amphibian' is the definition.
(I know that newt is a type of salamander)
'wife found in trap' is the wordplay.
'wife' becomes 'w' (abbreviation).
'found in' indicates putting letters inside.
'trap' becomes 'net' (net is a type of trap).
'w' inserted within 'net' is 'NEWT'.
(Other definitions for newt that I've seen before include "Amphibious creature" , "Amphibious salamander" , "Small, lizard-like amphibian" , "Went to find amphibian" , "Scientist" .)