Crazily train as mechanic (7)
I believe the answer is:
artisan
'mechanic' is the definition.
(I've seen this before)
'crazily train as' is the wordplay.
'crazily' indicates an anagram.
'train'+'as'='trainas'
'trainas' is an anagram of 'ARTISAN'.
(Other definitions for artisan that I've seen before include "Skilled craftsperson" , "Smith" , "Skilled manual 17" , "Sinatra (anag) -- skilled manual worker" , "Train as (anag) - craftsman" .)