[beis'klef]
低音谱号

[ noun ]
a clef that puts the F below middle C on the fourth line of a staff
<noun.communication>

Bass \Bass\, a.
Deep or grave in tone.

{Bass clef} (Mus.), the character placed at the beginning of
the staff containing the bass part of a musical
composition. [See Illust. under {Clef}.]

{Bass voice}, a deep-sounding voice; a voice fitted for
singing bass.


Clef \Clef\ (kl[e^]f; 277), n. [F. clef key, a key in music, fr.
L. clavis key. See {Clavicle}.] (Mus.)
A character used in musical notation to determine the
position and pitch of the scale as represented on the staff.

Note: The clefs are three in number, called the C, F, and G
clefs, and are probably corruptions or modifications of
these letters. They indicate that the letters of
absolute pitch belonging to the lines upon which they
are placed, are respectively C, F, and G. The F or bass
clef, and the G or treble clef, are fixed in their
positions upon the staff. The C clef may have three
positions. It may be placed upon the first or lower
line of the staff, in which case it is called soprano
clef, upon the third line, in which case it called alto
clef, or upon the fourth line, in which case tenor
clef. It rarely or never is placed upon the second
line, except in ancient music. See other forms of C
clef under C, 2.

{Alto clef}, {Bass clef}. See under {Alto}, {Bass}.