undulation

American  

[uhn-juh-ley-shuhn, uhn-dyuh-, -duh-] / ˌʌn dʒəˈleɪ ʃən, ˌʌn dyə-, -də- /

noun

1. an act of undulating; a wavelike motion.

2. a wavy form or outline.

3. one of a series of wavelike bends, curves, or elevations.

4. Physics.

   1. a wave.

   2. the motion of waves.

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undulation British  

/ ˌʌndjʊˈleɪʃən /

noun

1. the act or an instance of undulating

2. any wave or wavelike form, line, etc

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Etymology

Origin of undulation

First recorded in 1640–50; undul(ate) + -ation

Example Sentences

Her boss' stiff façade slips as his spine and joints move in a constant state of undulation.

From Salon • Jan. 18, 2025

The team didn’t see telltale signs of lateral undulation, the kind of movement that would indicate swimming played a prominent role in the evolutionary loss of limbs.

From Science Magazine • Sep. 26, 2023

Unlike in skeletal muscles, in the cell membrane of the heart muscle are finger-like discs that conduct the undulation required for pumping.

From Science Daily • Sep. 22, 2023

Eye-popping film of Gertie’s 1940 undulation and collapse became familiar to those in the 1950s who watched its repeated airings on the weekly ABC-TV series “You Asked For It.”

From Seattle Times • Jan. 12, 2023

He could feel the pulse and undulation of those great waves of magic, surging inside the child, never finding their way to shore.

From "The Girl Who Drank the Moon" by Kelly Barnhill