Possibly train as a mechanic (7)
I believe the answer is:
artisan
'a mechanic' is the definition.
(thesaurus)
'possibly train as' is the wordplay.
'possibly' indicates an anagram.
'train'+'as'='trainas'
'trainas' is an anagram of 'ARTISAN'.
(Other definitions for artisan that I've seen before include "Egypt peninsula; holy Mount" , "Skilled manual 17" , "one in command of craft?" , "Tsarina (anag.)" , "Skilled worker or craftsman" .)