upstroke

American  

[uhp-strohk] / ˈʌpˌstroʊk /

noun

1. an upward stroke, especially of a pen or pencil, or of a piston in a vertical cylinder.

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upstroke British  

/ ˈʌpˌstrəʊk /

noun

1. 1. an upward stroke or movement, as of a pen or brush

   2. the mark produced by such a stroke

2. the upward movement of a piston in a reciprocating engine

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Etymology

Origin of upstroke

First recorded in 1820–30; up- + stroke ¹

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Example Sentences

See Examples For:

upstroke

This is unusual because such an active upward wing movement, known as an upstroke, has previously been linked mainly to the flight mechanics of bats and insects rather than birds.

From Science Daily ● Oct. 17, 2026

Learning how nightjars generate thrust during the upstroke could help engineers develop more effective ways to move through the air.

From Science Daily ● Oct. 17, 2026

In our hippogriff, the muscles of the back drive the upstroke, and the muscles of the chest power the downstroke, just as in living bats and long-extinct pterosaurs.

From Scientific American ● Apr. 9, 2021

A hydrodynamic analysis of the humpback's movements in the lab confirmed that both the upstroke and the downstroke of its flippers provide forward thrust.

From National Geographic ● Jul. 12, 2017

The children of the Presidio school smirched their copybooks under the awful supervision, and poor Paquita, the prize pupil, failed utterly in that marvelous upstroke when her patron stood beside her.

From Selected Stories of Bret Harte by Bret Harte

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