Definition of actin
: a cellular protein found especially in microfilaments (such as those comprising myofibrils) and active in muscular contraction, cellular movement, and maintenance of cell shape
Recent Examples of actin from the Web
Like a pasta maker, the scale cell squeezes out and assembles a lattice of actins.
These example sentences are selected automatically from various online news sources to reflect current usage of the word 'actin'. Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.
Origin and Etymology of actin
International Scientific Vocabulary, from Latin actus
First Known Use: 1942
Definition of actin-
1 : having a radiate form actinolite
2 : actinic radiation (such as X-rays) actinometer
Origin and Etymology of actin-
New Latin, ray, from Greek aktin-, aktino-, from aktin-, aktis; perhaps akin to Old English ūhte morning twilight, Latin noct-, nox night — more at night
Seen and Heard
What made you want to look up actin? Please tell us where you read or heard it (including the quote, if possible).