Newton's first law
Also found in: Dictionary, Thesaurus, Wikipedia.
Newton's first law[′nüt·ənz ′fərst ′lȯ]
The law that a particle not subjected to external forces remains at rest or moves with constant speed in a straight line. Also known as first law of motion; Galileo's law of inertia.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.