He's in textiles (5)
I believe the answer is:
terry
'he's' is the definition.
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for terry that I've seen before include "Towelling material" , "Cotton pile fabric used for towels and bath robes" , "Fabric with piles" , "Loop of pile fabric; England footballer" , "Terence (dim.)" .)