Greeting a guard, not caught by a brave hero (8)
I believe the answer is:
hiawatha
'brave hero' is the definition.
'hiawatha' can be an answer for 'hero' (I have seen 'Indian hero' mean 'hiawatha' so perhaps 'hero' could also mean 'hiawatha'). I'm unsure of the 'brave' bit.
'greeting a guard not caught by a' is the wordplay.
'greeting' becomes 'hi' (hi is a kind of greeting).
'guard not' becomes 'wh' (I can't justify this - if you can you should give a lot more credence to this answer).
'caught' indicates putting letters inside.
'by' becomes 'at'.
'wh' enclosing 'at' is 'wath'.
'hi'+'a'+'wath'+'a'='HIAWATHA'
Can you help me to learn more?
(Other definitions for hiawatha that I've seen before include "Poetic Indian" , "Native American hero of Longfellow's poem" , "Indian hero of Longfellow's poem 'The Song of ... '" , "choice of subject for Longfellow" , "Longfellow's Onondaga Indian" .)