undulation

noun

un·​du·​la·​tion ˌən-jə-ˈlā-shən 

ˌən-dyə-, 

ˌən-də-

1

a

: a rising and falling in waves

b

: a wavelike motion to and fro 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

: the pulsation caused by the vibrating together of two tones not quite in unison

3

: a wavy appearance, outline, or form : waviness

Examples of undulation in a Sentence

Recent Examples on the Web

And these waves, the undulations on the surface of this water, propagate through the water. — Dina Genkina, IEEE Spectrum, 22 Jan. 2026

In fact, the follower is not even being subtle, with each undulation and pause of the ray being carefully scrutinized. — Melissa Cristina Márquez, Forbes.com, 17 Apr. 2026

The Concerto began boldly with a sense of undulation and sharp energy. — Sheila Regan, Twin Cities, 28 Mar. 2026

But in the fluctuating undulations of awards season, a good speech at the Globes can really boost an Oscar campaign. — Jake Coyle, Chicago Tribune, 11 Jan. 2026

Word History

First Known Use

1646, in the meaning defined at sense 1a

Rhymes for undulation

• abdication
• aberration
• abjuration
• abnegation
• abrogation
• acceptation
• acclamation
• acclimation
• accusation
• activation
• actuation
• acylation

Kids Definition

undulation

noun

un·​du·​la·​tion ˌən-jə-ˈlā-shən 

ˌən-d(y)ə-

1

: the action of undulating

2

: a wavy appearance or form : waviness