Luthier
Definition: one who builds or repairs stringed instruments
The word comes from “lute,” which was an early guitar.
Why I Looked It Up
I was driving home from the airport in Sioux Falls when I saw a new shop advertising itself as “Certified Luthiers.”
Postscript
Added on
From a profile of Yo Yo Ma in Spark: How Genius Ignites, From Child Prodigies to Late Bloomers:
…beginning with a reference from Isaac Stern, who had heard Ma play in Paris at the advice of a famed luthier named Étienne Vatelot.