Generous insurer presenting heart in gentleness (5)
I believe the answer is:
ample
'generous' is the definition.
(similar in meaning)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for ample that I've seen before include "No more, please!" , "Fully enough" , "Plentiful; capacious" , "Plentiful; large" , "Quite sufficient, more than enough" .)