Messenger carried by another messenger (6)
I believe the answer is:
hermes
'messenger' is the definition.
(Greek messenger god)
'carried by another messenger' is the wordplay.
'carried by' says the answer is hidden in the clue.
'HERMES' is hidden in the letters of 'another messenger'.
(Other definitions for hermes that I've seen before include "Greek messenger of the gods, like Roman Mercury" , "Greek god of commerce and theft" , "Winged messenger" , "Messenger and herald of the gods" , "Greek messenger god" .)