Hindu ascetic greeting US soldier (4)
I believe the answer is:
yogi
'hindu ascetic' is the definition.
(I've seen this in another clue)
'greeting us soldier' is the wordplay.
'greeting' becomes 'yo'.
'us soldier' becomes 'GI' (GI can mean an American soldier).
'yo'+'gi'='YOGI'
(Other definitions for yogi that I've seen before include "Cartoon bear; Hindu ascetic" , "Hindu mystic" , "master of posturing?" , "Someone practising certain Hindu disciplines" , "teacher of well-being" .)