Source : Webster's Revised Unabridged Dictionary (1913)

Ophicleide \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).