noun
couturier
koo-TOOR-ee-ay/kuˈtʊrieɪ/
A person who designs or makes high-fashion clothing.
The couturier pins a silk lapel while fitting the client's evening jacket.

Etymology
The dressmaking base plus an occupational ending names the person who practices the craft. Its fashion-designer sense places that work in the specialized world of high-end custom clothing.
More examples
- She hires a couturier to design her wedding gown.
- Several couturiers present their latest collections in Paris.
- The couturier chooses every fabric and supervises each fitting.
Forms
couturier · couturiers
couture noun — The design and making of high-fashion clothing.