ˌ ̷ ̷ ̷ ̷ˈlāshən noun
( -s )
Etymology: from (assumed) New Latin undulation-, undulatio, from Late Latin undula small wave + Latin -ation-, -atio -ation
1.
a. : a rising and falling in waves : heaving , pulsing , surging , swelling
the bay broke up into long oily undulations — Edith Wharton
b. : a wavelike motion to and fro, up and down, or from side to side in a fluid or elastic medium propagated continuously among its particles but with little or no permanent translation of the particles in the direction of the propagation : vibration
2.
a. : tremolo 1a
b. : the pulsation caused by the vibrating together of two tones not quite in unison
c. : vibrato
3. : a wavy appearance, outline, or form : a wavelike curve or series of curves : a rippling, rolling, or corrugated surface : waviness
the country spread all about us … rolling in gentle swells and undulations like a summer sea — Blanche E. Baughan
the undulations of his dark, old-fashioned locks of hair — Kay Boyle