actomyosin

noun

ac·to·my·o·sin ˌak-tə-ˈmī-ə-sən

: a contractile complex of actin and myosin that together with ATP is active during muscular contraction

Word History

Etymology

act(in) + -o- + myosin

First Known Use

1942, in the meaning defined above

Time Traveler

The first known use of actomyosin was in 1942

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act of sederunt

actomyosin

Acton

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Cite this Entry

Style

“Actomyosin.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/actomyosin. Accessed 3 Nov. 2025.

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Medical Definition

actomyosin

noun

ac·to·my·o·sin ˌak-tə-ˈmī-ə-sən

: a viscous contractile complex of actin and myosin concerned together with ATP in muscular contraction

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