1) Bass horn 2) Brass instrument 3) Choral instrument 4) English symphonic apparatus 5) English symphonic device 6) English melodic apparatus 7) English apparatus 8) English melodic device 9) English melodic instrument 10) English music apparatus 11) English musical equipment 12) English music instrument 1) Tuba 
The euphonium is a conical-bore, baritone-voiced brass instrument. The euphonium derives its name from the Greek word euphonos, meaning `well-sounding` or `sweet-voiced` (eu means `well` or `good` and phonos means `of sound`, so `of good sound`). The euphonium is a valved instrument; nearly all current models are piston valved, though ...
• (n.) A bass instrument of the saxhorn family.
brass wind instrument with valves, pitched in C or B an octave below the trumpet; it is the leading instrument in the tenor-bass range in military ... [1 related articles]
Eu·pho'ni·um noun [ New Latin See Euphony .] (Mus.) A bass instrument of the saxhorn family. 
The euphonium is a musical instrument of the saxhorn family. The bass saxhorn in B flat used in brass and military bands. Euphonium are used in the orchestra as a substitute for the superseded ophicleide.
[n] - a bass horn (brass wind instrument) that is the tenor of the tuba family
noun a bass horn (brass wind instrument) that is the tenor of the tuba family
Tenor four-valved brass band instrument of the bugle type, often mistaken for a tuba. It is used chiefly in brass and military bands
a brass musical instrument similar to the baritone tuba but somewhat smaller, with a wider bore and mellower tone, and often having a second bell.