actin

[ ak-tuhn ]

/ ˈæk tən /

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noun Biochemistry.

a globulin that is present in muscle plasma and that in connection with myosin plays an important role in muscle contraction.

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Origin of actin

1940–45; perhaps act + -in²

Other definitions for actin (2 of 2)

actin-

variant of actino- before a vowel: actinism.

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2022

How to use actin in a sentence

"Oi don't loike th' way he is actin', Frankie," whispered Barney.
Frank Merriwell's Bravery|Burt L. Standish
Can't you hear millions spoke of without actin' like a blasted whistlin' buoy?
Isle o' Dreams|Frederick F. Moore
And when he quit he went off toward home, slappin' his fists together and actin' as if he didn't see the road across his bows.
Cy Whittaker's Place|Joseph C. Lincoln
Ed was actin at Niblo's Garding, which looks considerable more like a parster than a garding, but let that pars.
The Best of the World's Classics, Restricted to Prose, Vol. X (of X) - America - II, Index|Various

I don't know what them skunks think they can do, actin' in this way.
Motor Matt's Daring Rescue|Stanley R. Matthews

British Dictionary definitions for actin

actin

/ (ˈæktɪn) /

noun

a protein that participates in many kinds of cell movement, including muscle contraction, during which it interacts with filaments of a second protein, myosin

Word Origin for actin

C20: from act + -in

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medical definitions for actin

actin

[ ăk′tĭn ]

One of the protein components found in muscle, existing as F-actin or G-actin, into which actomyosin can be split and which acts with myosin in muscle contraction.

Scientific definitions for actin

actin

[ ăk′tĭn ]

A protein found in all eukaryotic cells, forming filaments that make up a main component of the cell's supporting matrix or cytoskeleton. Actin and the protein myosin together make up the contractile units (called sarcomeres) of skeletal muscle fibers.