Powerful transport turning right to start with (9)
I believe the answer is:
trenchant
'powerful' is the definition.
(thesaurus)
'transport turning right to start with' is the wordplay.
'transport' becomes 'enchant' ('enchant' can be a synonym of 'transport'**).
'turning' says the letters should be written in reverse.
'right' becomes 'rt'.
'to start with' is a charade indicator (letters next to each other).
'rt' reversed gives 'tr'.
'enchant' put after 'tr' is 'TRENCHANT'.
(Other definitions for trenchant that I've seen before include "Incisive in expression" , "Vigorous, incisive" , "Vigorous and effective" , "Clear" , "Keen" .)