Social climber puts convertible on craft (7)
I believe the answer is:
upstart
'social climber' is the definition.
(term for someone seeking higher social status)
'puts convertible on craft' is the wordplay.
'convertible' indicates anagramming the letters.
'on' is a charade indicator (letters next to each other).
'craft' becomes 'art' (both can mean cunning or trickery).
'puts' is an anagram of 'upst'.
'upst'+'art'='UPSTART'
(Other definitions for upstart that I've seen before include "Nouveau riche" , "Person who has suddenly risen in wealth or importance" , "One who has risen suddenly to high position, and is arrogant with it" , "Arrogant newcomer" , "Brash newcomer" .)