Noun
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.
Source: Webster's dictionarySax created an instrument with a single-reed mouthpiece like a clarinet, conical brass body like an ophicleide, and some acoustic properties of both the horn and the clarinet. Source: Internet
The ophicleide, which was used in bands and orchestras for a few decades in the early to mid-19th century, used a system of keys and was an improvement over the serpent but was still unreliable, especially in the high register. Source: Internet