undulate

American  

[uhn-juh-leyt, uhn-dyuh-, -duh-, uhn-juh-lit, -leyt, uhn-dyuh-, -duh-] / ˈʌn dʒəˌleɪt, ˈʌn dyə-, -də-, ˈʌn dʒə lɪt, -ˌleɪt, ˈʌn dyə-, -də- /

verb (used without object)

undulated, undulating

1. to move with a sinuous or wavelike motion; display a smooth rising-and-falling or side-to-side alternation of movement.

   The flag undulates in the breeze.

2. to have a wavy form or surface; bend with successive curves in alternate directions.

3. (of a sound) to rise and fall in pitch.

   the wail of a siren undulating in the distance.

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verb (used with object)

undulated, undulating

1. to cause to move in waves.

2. to give a wavy form to.

adjective

1. Also undulated having a wavelike or rippled form, surface, edge, etc.; wavy.

undulate British  

/ ˈʌndjʊˌleɪt /

verb

1. to move or cause to move in waves or as if in waves

2. to have or provide with a wavy form or appearance

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adjective

1. having a wavy or rippled appearance, margin, or form

   an undulate leaf

Other Word Forms

• nonundulate adjective
• undulator noun

Etymology

Origin of undulate

First recorded in 1650–60; from Latin undulātus waved, equivalent to und(a) “wave” + -ul(a) -ule + -ātus -ate ¹

Explanation

Undulate means to move in a wave-like pattern. If a sound increases and decreases in pitch or volume like waves, you can say the sound is undulating. When searching for the lost boy, the rescuers' cries undulated through the forest. The verb undulate comes from the Latin word undula, which means "wavelet" (unda means "wave"). So any action shown with the verb undulate has that waving sense to it. If something moves in a wavy, pattern, for example, it is said to undulate. The wind might cause prairie grass to undulate, or music might cause hips to undulate.

Example Sentences

The heavy concrete roof is actually suspended just above the walls, and seems to undulate, letting more light through in a thin opening above the altar.

From The Wall Street Journal • Mar. 6, 2026

In the area with cold plunging and a sauna, the walls undulate with patterns that change color, designed to evoke arctic caves and volcanic rock.

From Los Angeles Times • Feb. 18, 2026

Like I said before, most worms on planet Earth—well, those visible to the naked eye— have a lot of chambers and undulate, which isn’t very sandworm-ish.

From Slate • Mar. 8, 2024

A helical structure on the underside of the sheet rotates like a corkscrew to cause the carpet to undulate and create a travelling wave on the water.

From Science Daily • Dec. 4, 2023

In the firelight, Miss Miss seemed to undulate in some ancient dance.

From "Beauty Queens" by Libba Bray

Related Words

• billow
• wobble