Definition of "invariable" []

• Not changing or subject to change; constant. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "It is this that constitutes the invariable laws of motion: I say _invariable_, because they can never change, without producing confusion in the essence of things."
• "The article is invariable, that is, does not change in form when used with plural nouns, as "la viro", the man, "la viroj", the men."
• "Dan Treu grinned as he recalled the invariable exchange of personalities when they met."