Take away first of trunks, transported back (7)
I believe the answer is:
detract
'take away' is the definition.
(I know that take away can be written as detract)
'first of trunks transported back' is the wordplay.
'first of trunks' becomes 't' (1st letter of 'trunks').
'transported' becomes 'carted' (carting is a kind of transporting).
'back' shows that the letters should be reversed in order.
't'+'carted'='tcarted'
'tcarted' written backwards gives 'DETRACT'.
(Other definitions for detract that I've seen before include "Derogate" , "Slight" , "Belittle" , "Take away from, diminish" , "Take away a part of, lower in value" .)