n. 波动, 波状弯曲, 起伏

[医] 波动

Undulation \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. --Evelyn.

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 {beat}.

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; a vibration.