One spearing trout-like fish — it might be easy (5)
I believe the answer is:
chair
'it might be easy' is the definition.
(as in an easy chair)
'one spearing trout-like fish' is the wordplay.
'one' becomes 'i' (Roman numeral).
'spearing' is an insertion indicator (some letters spear through others).
'trout-like fish' becomes 'char' (type of fish).
'i' placed within 'char' is 'CHAIR'.
(Other definitions for chair that I've seen before include "Something with legs" , "Official position of authority" , "Windsor, for example" , "Seat for one person" , "director at meeting" .)