bass

Bass describes a very low range of musical notes or a person or instrument that produces those notes. (adjective)

An example of bass is the part that is sung below the baritone in a male barbershop quartet.
An example of someone who had a bass voice is Louis Armstrong.

Bass is the lowest part of the musical scale. (noun)

An example of the part of a music that is bass is the singing voice under the baritone in a male barbershop quartet.
An example of an instrument that is bass is the guitar.

See bass in Webster's New World College Dictionary

noun

the range of the lowest male voice, usually from middle C to two or more octaves below
1. a voice or singer with such a range
2. an instrument with a similar range within its family; specif., a double bass
3. a part for such a voice or instrument
a low, deep sound or tone, as of a voice with this range
in four-part harmony, the lowest part
the lower part of the audio-frequency band in sound reproduction

adjective

of, for, or having the range of a bass

noun pl. bass or basses

any of various families of spiny-finned percoid, food and game fishes of fresh or salt water, including black bass, rock bass, and striped bass

noun

See bass in American Heritage Dictionary 4

(băs)

noun pl. bass bass or bass·es

Any of several North American freshwater fishes of the family Centrarchidae, related to but larger than the sunfishes.
Any of various marine fishes of the family Serranidae, such as the sea bass and the striped bass.

(bās)

noun

A low-pitched sound or tone.
The tones in the lowest register of an instrument.
a. A male singing voice of the lowest range.
b. A singer who has such a voice.
c. An instrument that sounds within this range.
d. Abbr. B A vocal or instrumental part written within this range.
An instrument, especially a double bass, that produces tones in a low register.

adjective