Indian prince beheaded by Greek hero (4)
I believe the answer is:
ajax
'greek hero' is the definition.
(I've seen this before)
'indian prince beheaded by' is the wordplay.
'indian prince' becomes 'raja' (I've seen this before).
'beheaded' means to remove the first letter.
'by' becomes 'x' (multiplication sign).
'raja' with its initial letter removed is 'aja'.
'aja'+'x'='AJAX'
(Other definitions for ajax that I've seen before include "old privy" , "Greek hero of the Trojan war - Dutch football team" , "Legendary hero" , "Old war hero" , "Mythical Greek hero, who fought against Troy" .)