See more synonyms for constant on
  1. not changing or varying; uniform; regular; invariable: All conditions during the three experiments were constant.
  2. continuing without pause or letup; unceasing: constant noise.
  3. regularly recurrent; continual; persistent: He found it impossible to work with constant interruption.
  4. faithful; unswerving in love, devotion, etc.: a constant lover.
  5. steadfast; firm in mind or purpose; resolute.
  6. Obsolete. certain; confident.
  1. something that does not or cannot change or vary.
  2. Physics. a number expressing a property, quantity, or relation that remains unchanged under specified conditions.
  3. Mathematics. a quantity assumed to be unchanged throughout a given discussion.

Origin of constant

1350–1400; Middle English < Latin constant- (stem of constāns, present participle of constāre to stand firm), equivalent to con- con- + stā- stand + -nt- present participle suffix
Related formscon·stant·ly, adverbnon·con·stant, noun, adjectiveo·ver·con·stant, adjectiveo·ver·con·stant·ly, adverbo·ver·con·stant·ness, nounqua·si-con·stant, adjectivequa·si-con·stant·ly, adverbun·con·stant, adjectiveun·con·stant·ly, adverb

Synonyms for constant

See more synonyms for on
1. unchanging, immutable, permanent. 2. perpetual, unremitting, uninterrupted. 3. incessant, ceaseless. 4. loyal, staunch, true. See faithful. 5. steady, unwavering, unswerving.

Antonyms for constant

1. changeable. 2. fitful. 3. sporadic. 4. unreliable. 5. wavering. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for constantly

regularly, steadily, invariably, continually

Examples from the Web for constantly

Contemporary Examples of constantly

Historical Examples of constantly

  • But she constantly recalls what that snobbish Bines was unfair enough to tell her.

    The Spenders

    Harry Leon Wilson

  • That he was constantly cheerful proved the matter of his musings to be pleasant.

    The Spenders

    Harry Leon Wilson

  • It was his habit to affect that he constantly forgot his mother's name.

    The Spenders

    Harry Leon Wilson

  • He was married, but constantly said he was about to leave his wife, so she would divorce him.

    The Spenders

    Harry Leon Wilson

  • He is constantly stopping or turning his horses to the sidewalk, right or left.

British Dictionary definitions for constantly


  1. fixed and invariable; unchanging
  2. continual or continuous; incessantconstant interruptions
  3. resolute in mind, purpose, or affection; loyal
  1. something that is permanent or unchanging
  2. a specific quantity that is always invariablethe velocity of light is a constant
    1. mathsa symbol representing an unspecified number that remains invariable throughout a particular series of operations
    2. physicsa theoretical or experimental quantity or property that is considered invariable throughout a particular series of calculations or experiments
  3. See logical constant
Derived Formsconstantly, adverb

Word Origin for constant

C14: from Old French, from Latin constāns standing firm, from constāre to be steadfast, from stāre to stand


  1. Benjamin (bɛ̃ʒamɛ̃). real name Henri Benjamin Constant de Rebecque. 1767–1830, French writer and politician: author of the psychological novel Adolphe (1816)
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 constantly



late 14c., "steadfast, resolute," from Old French constant (14c.) or directly from Latin constantem (nominative constans) "standing firm, stable, steadfast, faithful," present participle of constare, from com- "together" (see com-) + stare "to stand," from PIE root *sta- "to stand" (see stet). Of actions and conditions from 1650s. Related: Constantly.



1832 in mathematics and physics, from constant (adj.).

Online Etymology Dictionary, © 2010 Douglas Harper

constantly in Medicine


  1. Continually occurring; persistent.
  2. Unchanging in nature, value, or extent; invariable.
  1. A quantity assumed to have a fixed value in a specified mathematical context.
  2. An experimental or theoretical condition, factor, or quantity that does not vary or that is regarded as invariant in specified circumstances.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

constantly in Science


  1. A quantity that is unknown but assumed to have a fixed value in a specified mathematical context.
  2. A theoretical or experimental quantity, condition, or factor that does not vary in specified circumstances. Avogadro's number and Planck's constant are examples of constants.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

constantly in Culture


A number that appears in equations and formulas and does not vary or change. Examples are Planck's constant and the speed of light.

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.