from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A protein found in muscle that together with myosin functions in muscle contraction.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A globular structural protein that polymerizes in a helical fashion to form an actin filament (or microfilament).
- n. One of the six isoforms of actin.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. one of the proteins into which actomyosin can be split; can exist in either a globular or a fibrous form
Latin āctus, motion; see act + -in.(American Heritage® Dictionary of the English Language, Fourth Edition)
From Ancient Greek ἀκτίς (aktis, "ray"), based on the shape of the filament formed, and the English chemical suffix -in. (Wiktionary)