In Bethlehem I greeted one who has left home (6)
I believe the answer is:
emigre
'one who has left home' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'in bethlehem i greeted' is the wordplay.
'in' indicates the answer is hidden within the clue.
'EMIGRE' can be found hidden inside 'bethlehem i greeted'.
Can you help me to learn more?
(Other definitions for emigre that I've seen before include "Traveller to another country" , "Political refugee, especially a royalist fleeing the French Revolution" , "One leaving their nation" , "A political exile from regime" , "One leaving country for political reasons" .)