[ in-vair-ee-uh-buhl ]
/ ɪnˈvɛər i ə bəl /


not variable; not changing or capable of being changed; static or constant.


something that is invariable; a constant.

Nearby words

  1. invalidity,
  2. invalidity benefit,
  3. invaluable,
  4. invar,
  5. invariability,
  6. invariably,
  7. invariance,
  8. invariant,
  9. invariant mass,
  10. invasion

Origin of invariable

late Middle English word dating back to 1400–50; see origin at in-3, variable

Related formsin·var·i·a·bil·i·ty, in·var·i·a·ble·ness, nounin·var·i·a·bly, adverb Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for invariable

British Dictionary definitions for invariable


/ (ɪnˈvɛərɪəbəl) /


not subject to alteration; unchanging


a mathematical quantity having an unchanging value; a constant
Derived Formsinvariability or invariableness, noun

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

Word Origin and History for invariable



early 15c., from Old French invariable (14c.) and directly from Medieval Latin invariabilis, from in- "not, opposite of" (see in- (1)) + variabilis (see variable). Related: Invariably.

Online Etymology Dictionary, © 2010 Douglas Harper