He, Clive, designed a carrier (7)
I believe the answer is:
vehicle
'a carrier' is the definition.
(thesaurus)
'he clive designed' is the wordplay.
'designed' indicates anagramming the letters (designed with the letters).
'he'+'clive'='heclive'
'heclive' is an anagram of 'VEHICLE'.
(Other definitions for vehicle that I've seen before include "Eg, car" , "Means of conveyance" , "Medium" , "Conveyance of people or things" , "4 x 4" .)