Endlessly courageous on a Spanish Costa (5)
I believe the answer is:
brava
'spanish costa' is the definition.
(I've seen this before)
'endlessly courageous on a' is the wordplay.
'endlessly' means to remove the last letter.
'courageous' becomes 'brave' (synonyms).
'on' says to put letters next to each other.
'brave' with its last letter taken off is 'brav'.
'brav'+'a'='BRAVA'
(Other definitions for brava that I've seen before include "See 17" , "Approving cry (to diva)" , "1 across - - , Sp. coastal region" , "Excellent" , "Well done!" .)