Chap accommodating Australian native, cast away (6)
I believe the answer is:
maroon
'cast away' is the definition.
(thesaurus)
'chap accommodating australian native' is the wordplay.
'chap' becomes 'man' (chap can mean a man).
'accommodating' indicates putting letters inside.
'australian native' becomes 'roo' (informal term for kangaroo).
'man' placed around 'roo' is 'MAROON'.
(Other definitions for maroon that I've seen before include "Could be a warning signal" , "Strand - reddish colour" , "Abandon on island, or a brownish-red colour" , "desert" , "Slaves' descendant" .)