Un`du*la"tion (?), n. [Cf. F.
ondulation.] 1. The act of undulating; a waving
motion or vibration; as, the undulations of a fluid, of water, or of
air; the undulations of sound.
2. A wavy appearance or outline; waviness.
3. (Mus.) (a) The tremulous
tone produced by a peculiar pressure of the finger on a string, as of a
violin. (b) The pulsation caused by the
vibrating together of two tones not quite in unison; -- called also
4. (Physics) A motion to and fro, up and
down, or from side to side, in any fluid or elastic medium, propagated
continuously among its particles, but with no translation of the particles
themselves in the direction of the propagation of the wave; a wave motion;