Private planes or trains (8)
I believe the answer is:
personal
'private' is the definition.
(similar in meaning)
'planes or trains' is the wordplay.
'trains' indicates anagramming the letters (train can mean to grow something into a shape).
'planes'+'or'='planesor'
'planesor' with letters rearranged gives 'PERSONAL'.
(Other definitions for personal that I've seen before include "Intimate - in the flesh" , "Confidential" , "Of one individual" , "Relating to the individual" , "Wounding" .)