A fish I caught -- or mushroom? (6)
I believe the answer is:
agaric
'mushroom?' is the definition.
(mushroom is a kind of agaric)
'a fish i caught' is the wordplay.
'fish' becomes 'gar' (gar is a kind of fish**).
'caught' becomes 'c' (cricket abbreviation).
'a'+'gar'+'i'+'c'='AGARIC'
'or' acts as a link.
(Other definitions for agaric that I've seen before include "Type of mushroom" , "Fungus, eg, mushroom" , "fungal growth" , "Fungus of mushroom family" .)