A stiletto is a kind of dagger, optimized to function as a stabbing weapon exclusively. Generally it has little to no cutting edges, being essentially a long, thin spike with a needle-like point mounted to a handle.
The stiletto originated in late 15th century Italy. As a result of its abilities to penetrate thick clothing and even mail, and to inflict lethal wounds with comparatively less external bleeding, as well as being easy to conceal, it became the favored weapon of the medieval assassin.
Notably used by Yor Briar.