Textile worker perhaps you once introduced to doctor (4)
I believe the answer is:
dyer
'textile worker' is the definition.
(I've seen this in another clue)
'you once introduced to doctor' is the wordplay.
'you once' becomes 'ye' (historical version of 'you').
'introduced to' means one lot of letters goes inside another.
'doctor' becomes 'dr' (abbreviation).
'ye' going into 'dr' is 'DYER'.
'perhaps' is the link.
(Other definitions for dyer that I've seen before include "Cloth colourer" , "One who stains cloth" , "Brunette trying to be blonde" , "Cloth worker" , "Adder of colour" .)