Message carrier with a lofty target (6,6)
I believe the answer is:
homing pigeon
'message carrier' is the definition.
'homing pigeon' can be an answer for 'carrier' (thesaurus). I'm not certain of the 'message' bit.
I cannot understand how the remainder of the clue works.
(Other definitions for homing pigeon that I've seen before include "Trained flier" , "Messenger bird" , "Trained bird" .)