undulation

noun un·du·la·tion \ ˌən-jə-ˈlā-shən , ˌən-dyə- , ˌən-də- \

|Updated on: 23 Jul 2018

Definition of undulation

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

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Recent Examples of undulation from the Web

While Washington has long ago grown numb to Trump’s unrelenting mayhem, the president’s two days of undulations in Brussels, rolling between enraged criticism and boastful, happy proclamations, left many leaders feeling queasy.

— james hohmann, Washington Post, "The Daily 202: GOP candidates caught in a bind on Medicaid," 13 July 2018
And the sleek vertical lines are a counterpart to the horizontal undulations of the soon-to-open transit center next door.

— john king, SFChronicle.com, "New nimble, frisky SoMa tower fits neatly into surroundings," 6 July 2018
The green is elevated and features plenty of undulation, making this a true test from start to finish.

— brent kennedy, Howard County Times, "Worthington Manor Golf Club," 29 June 2018
The greens are incredibly large, meaning that golfers will inevitably face several long putts going up, down and around multiple hills and undulations.

— brent kennedy, The Aegis, "Mountain Branch Golf Club," 22 June 2018
The wiry undulations of the Slinky toy, for example, turn out to be good way of modeling sine waves.

— paul grimstad, The New Republic, "Can You Measure How Good a Song Is?," 21 June 2018
The hole then bends to the left and continues slightly downhill to one of the toughest greens on the course, featuring a false front and plenty of undulation.

— brent kennedy, Howard County Times, "Whiskey Creek Golf Club," 20 June 2018
The rover has measured a few more methane spikes, but the new wrinkle is the undulations in the low background levels — higher in summer than winter.

— kenneth chang, New York Times, "Life on Mars? Rover’s Latest Discovery Puts It ‘On the Table’," 7 June 2018
That’s part of the beauty of the course with natural undulations and multiple ways to get around it.

— drew davison, star-telegram, "For its 50th anniversary, the Byron Nelson golf tournament sets a new course | Fort Worth Star-Telegram," 16 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'undulation.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.