Endless courage results in try (4)
I believe the answer is:
hear
'try' is the definition.
(as in to try someone in court or hear their case)
'endless courage' is the wordplay.
'endless' means to remove the last letter.
'courage' becomes 'heart' (heart is a kind of courage).
'heart' with its final letter taken away is 'HEAR'.
'results in' acts as a link.
(Other definitions for hear that I've seen before include "Perceive audibly" , "receive information" , "learn" , "Listen to" , "Perceive aurally" .)