Courageous behaviour shown by tall, rangy rebels (9)
I believe the answer is:
gallantry
'courageous behaviour' is the definition.
(I've seen this before)
'by tall rangy rebels' is the wordplay.
'by' is a charade indicator (letters next to each other).
'rebels' is an anagram indicator.
'tall' after 'rangy' is 'rangytall'.
'rangytall' is an anagram of 'GALLANTRY'.
'shown' is the link.
(Other definitions for gallantry that I've seen before include "Bravery" , "Courageous behaviour" , "Valour" , "Heroism" , "Spirit of adventure" .)