Seaman gets new beginning — he’s working in menswear (6)
I believe the answer is:
tailor
'he's working in menswear' is the definition.
(someone who makes suits for men)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for tailor that I've seen before include "Maker of men's suits" , "One makes suits etc. to measure" , "Couturier" , "fitter" , "Cut" .)