Hour taken to feed young bear fish (4)
I believe the answer is:
chub
'fish' is the definition.
(chub is a kind of fish)
'hour taken to feed young bear' is the wordplay.
'hour' becomes 'h' (abbreviation).
'taken to feed' is an insertion indicator (inserted letters are 'fed' to others).
'young bear' becomes 'cub' (I've seen this before).
'h' put into 'cub' is 'CHUB'.
(Other definitions for chub that I've seen before include "Thick-bodied European fish" , "Small river fish of the carp family" , "Fat freshwater fish" , "Fat relative of the carp" , "River fish; rhymes with public house" .)