Somehow trains a craftsman (7)
I believe the answer is:
artisan
'craftsman' is the definition.
(synonyms)
'somehow trains a' is the wordplay.
'somehow' indicates an anagram.
'trains'+'a'='trainsa'
'trainsa' anagrammed gives 'ARTISAN'.
(Other definitions for artisan that I've seen before include "Skilled worker at craft or trade" , "Skilled tradesman" , "Tsarina (anag.)" , "Smith" , "Crafty sort" .)