Awaiting delivery (2,5)
'awaiting delivery' is the definition.
(I've seen this before)
This is the entire clue.
(Another definition for on order that I've seen is " Awaiting delivery".)
I'm afraid I can't even guess how this answer relates to the clue.
Can you help me to learn more?
(Other definitions for unborn that I've seen before include "Not yet given birth to" , "In utero" , "Yet to be delivered" , "(Of baby) not delivered" , "Still in the womb" .)