Basset Horn Definition

băsĭt

noun

A tenor clarinet, pitched in F, having a wider bell and greater range than a standard clarinet.

American Heritage

A kind of clarinet pitched in F and ending in a brass bell: its range lies between those of the common clarinet and the bass clarinet.

Webster's New World

An alto instrument of the clarinet family, pitched in F below middle C, with a range reaching down to F below that.

Wiktionary

Origin of Basset Horn

Partial translation of German Bassetthorn Bassett type of low-pitched string instrument (ultimately from Italian basso low basso) Horn horn (from the resemblance of early crescent-shaped models to hunting horns)

From American Heritage Dictionary of the English Language, 5th Edition
From German Bassetthorn, translation of French cor de bassette, from Italian corno di bassetto.

From Wiktionary