2.  Something resembling such an instrument in shape or sound, as:
a.  The round, flared opening of a wind instrument at the opposite end from the mouthpiece.
b.   bells A percussion instrument consisting of metal tubes or bars that emit tones when struck.
c.  A hollow, usually inverted vessel, such as one used for diving deep below the surface of a body of water.
d.  The corolla of a flower: "In a cowslip's bell I lie" (Shakespeare).
e.  The body of a jellyfish.
 3.  Nautical  a.  A stroke on a hollow metal instrument to mark the hour.
b.  The time indicated by the striking of this instrument, divided into half hours.