Marian trained to be a pilot, perhaps (6)
I believe the answer is:
airman
'a pilot perhaps' is the definition.
(pilot is a kind of airman)
'marian trained' is the wordplay.
'trained' indicates an anagram (to train can mean to grow something into a shape).
'marian' with letters rearranged gives 'AIRMAN'.
'to be' acts as a link.
(Other definitions for airman that I've seen before include "He flies" , "Male flyer" , "Flier" , "crew member" , "Aviator" .)