Somehow trains a worker (7)
I believe the answer is:
artisan
'worker' is the definition.
(someone skilled in a particular craft)
'somehow trains a' is the wordplay.
'somehow' is an anagram indicator.
'trains'+'a'='trainsa'
'trainsa' with letters rearranged gives 'ARTISAN'.
(Other definitions for artisan that I've seen before include "Skilled worker at craft or trade" , "Technician" , "Skilled worker or craftsman" , "Tsarina (anag.)" , "Mechanic" .)