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

Example Sentences

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 major part of the current flow is the high, thin upstroke of the "R" wave; the thin downstroke is simply return to the base line.

From Time Magazine Archive

The heart relaxes and refills on the upstroke.

From Time Magazine Archive

There were words on the paper, written in stiff German characters, orthodox and methodical in every turn and upstroke and formal pothook.

From Dreams and Dream Stories by Kingsford, Anna Bonus