Emissary behind hosts, for example (6)
I believe the answer is:
legate
'emissary' is the definition.
(legate is a kind of emissary)
'behind hosts for example' is the wordplay.
'behind' becomes 'late' (as in behind schedule).
'hosts' indicates putting letters inside (inserted letters are welcomed or hosted).
'for example' becomes 'e.g.' (short for 'exempli gratia', 'for example' in Latin).
'late' placed around 'eg' is 'LEGATE'.
(Other definitions for legate that I've seen before include "Official emissary" , "Vatican emissary" , "papal emissary" , "Official representative" , "Envoy, maybe papal" .)