Definition of upstroke in English:

upstroke

noun

  • A stroke made upward.

    ‘the upstroke of the whale's tail’
    • ‘The course package consists of training in how to shape letters, analysis of alphabets, upstrokes, horizontal strokes, curves, zigzag lines and exercises in rhythm drills, drawing of parallel lines and drawing of circles.’
    • ‘Air compressed on the upstroke helps push the piston back down, minimizing energy loss.’
    • ‘This limb action would be relatively inefficient compared with that of modern animals such as penguins, whose wings produce propulsive force throughout virtually the whole of the upstroke and downstroke.’
    • ‘Thus, lift forces exerted on the hindlimbs may explain why bats inspire during the downstroke of their wings and expire during the upstroke.’
    • ‘In bats and birds in air, lift is generated by the upstroke at high flight speeds, but not at low speeds.’
    • ‘The video shows a bird with white in a big rectangle all the way across the trailing edges of both upperwings - white that is visible on both the upstroke and the downstroke - long wings - powerful flight - like nothing I've ever seen.’

Pronunciation:

upstroke

/ˈəpˌstrōk/