\Oph"i*cleide\, n. [F. ophicl['e]ide, fr. Gr. 'o`fis
a serpent + ?, gen. ?, a key. So named because it was in
effect the serpent, an old musical instrument, with keys
added.] (Mus.)
A large brass wind instrument, formerly used in the orchestra
and in military bands, having a loud tone, deep pitch, and a
compass of three octaves; -- now generally supplanted by bass
and contrabass tubas. --Moore (Encyc. of Music).