Trains a poorly skilled worker (7)
I believe the answer is:
artisan
'skilled worker' is the definition.
(an artisan is a skilled craftsperson)
'trains a poorly' is the wordplay.
'poorly' is an anagram indicator (a poor spelling).
'trains'+'a'='trainsa'
'trainsa' with letters rearranged gives 'ARTISAN'.
(Other definitions for artisan that I've seen before include "Mechanic" , "Skilled craftsperson" , "Skilled worker at craft or trade" , "Skilled manual 17" , "Egypt peninsula; holy Mount" .)