I'm somewhat vexed in that I cannot think of a word that means a "promise breaker" or "person who breaks a promise". There are words that may subsume that, such as "miscreant" or "liar", but I cannot come up with an English word that is limited to a person who breaks promises.

The closest I've come is "piker", which is (a) informal and (b) limited to Australia/NZ, but means (according to the dictionary on my Mac):

a person who withdraws from a commitment.

Is there a more formal and common word that can be used to refer to people who break promises?

  • What about disloyal?
    – N.N.
    Oct 5, 2011 at 15:17
  • @N.N. aside from /disloyal/ seeming to relate more to allegiance than obligation, /disloyal/ is an adjective not a noun. (A person is not "a disloyal", though they may be "a piker"). Good thought, though. Oct 5, 2011 at 15:28
  • Are you looking for a single word that covers both willful (liar) and non-willful (flake) cases? Or just one of those? Oct 5, 2011 at 15:45
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    "Liar" is the word that comes to mind in a willful context (e.g., "Most politicians are liars!"). "Dishonoured" or "failed" are two words that come to mind in a non-willful context (e.g., "the payment was dishonoured by insufficient funds in the bank account" and "the new employee failed to arrive at the office on time," respectively). Oct 5, 2011 at 17:07
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    @Randolf: But "liar" is more general. If I say, "Bob took your book" when it was really me who did it, I am a liar, but I have not broken any promise.
    – Jay
    Oct 7, 2011 at 16:47

12 Answers 12



renege, renegue vb (intr; often foll by on)
to go back (on one's promise, etc.)
reneger , reneguer n

Reneger vs. oath breaker ngram:

ngram of 'reneger' and 'oath breaker' 1920-2010, reneger leading in use approx 1960, oath breaker leading in use approx 1930s and early 2000s

  • 11
    "Renege" is indeed the conventional verb to use for this idea. But while the dictionary lists "reneger" as a noun, I'm hard-pressed to recall ever seeing it used in real text. (Not that I can think of an alternative word.)
    – Jay
    Oct 5, 2011 at 17:54
  • 2
    That's what happens with "one word" requests. There may be none that is well-known.
    – GEdgar
    Oct 5, 2011 at 18:51
  • I don't think we're going to get any closer than this. Oct 5, 2011 at 18:57
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    I would highly advise against using this word in converstation unless you have complete faith in your ability to pronounce it properly and clearly. It is just way too close to this word: english.stackexchange.com/questions/9824/…
    – T.E.D.
    Oct 5, 2011 at 19:35
  • 2
    @KarlKnechtel Sometimes I wonder if the percentages on some of these ngrams aren't so small as to effectively make them noise graphs.
    – T.E.D.
    Oct 6, 2011 at 13:18

A personal favorite slang term for an unreliable person is a flake. A flake says they are going to do something and then they don't follow through. The definition is not limited to promise breaking, however.

  • 1
    Yeah, not limited to promise breaker, but it's a good word in the context though. My mother used the word "flakey" a lot. Oct 5, 2011 at 15:23
  • 12
    Is it okay to refer to an unreliable corn farmer as a "corn flake?" ;D Oct 5, 2011 at 17:16

There's "oathbreaker". It isn't very common these days though.

  • Not in regular speech... way common in fantasy literature, though.
    – neminem
    Aug 16, 2013 at 18:24

Warlock - if you're into really Old English:

Middle English warloghe, from Old English wrloga, oath-breaker : wr, pledge; see wr-o- in Indo-European roots + -loga, liar (from logan, to lie; see leugh- in Indo-European roots).

(Note: the link originally went to Wikipedia's Warlock, which had a brief description, including roughly the oathbreaker meaning. Apparently the word has changed, to a D&D character...)

  • 3
    I love this as a historical meaning. However, today it is pretty much universally understood to be "somebody (typically male) who practices magic". If you try to use it for the meaning above, you will probably be misunderstood.
    – T.E.D.
    Aug 16, 2013 at 18:15

This may be US specific, but I have used Welcher used for promises as well as bets.

  • 1
    It's not US only, but it's slang and is best avoided as it can be offensive to Welsh people. etymonline.com/index.php?term=welch boards.straightdope.com/sdmb/showthread.php?t=417491
    – Hugo
    Oct 5, 2011 at 16:59
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    I remember someone once using the word "gypped" in high school, which caused one girl to object -- she explained that she is of Gypsy heritage and that this word reflects poorly on her background in an unjust manner. (I thought she made a fair point, and out of respect for people in general I've made an effort to eliminate these sorts of words from my casual speech as I discover their meanings; this has been a challenge because I've never encountered a list of such words.) Oct 5, 2011 at 17:13
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    @RandolfRichardson That might make a good question ... Oct 5, 2011 at 19:09
  • 1
    @RandolfRichardson: Great attempt; I'm sorry for the reaction it got, but I do think it was a great idea. I wonder if someday it'll be revived and accepted. Oct 6, 2011 at 14:06
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    @Brian M. Hunt: Once you mentioned it I thought "yeah, that would be a good question" but I guess both of us are still "learning the ropes" around here. :) Oct 7, 2011 at 19:53

Is there a word for a “promise breaker”?

Yes, there is: break-promise!

And yes, this is a person who breaks a promise. It was used by no less than William Shakespeare in As You Like It and is in a category of nouns called cutthroat compounds.

According to Encyclopedia Briannica:

Cutthroats are compounds that name people and things by describing what they do. Cutthroats are made from a transitive verb and a noun, where the noun is the direct object of the verb.

So a cutthroat is not a throat but a pirate who cuts throats; a scarecrow is not a crow but a thing that scares crows; a Shakespeare is a person who originally shook spears; and a break-promise is a person who breaks promises.

Some other break- cutthroats:

  • break-bones (an osprey)
  • break-club (an obstacle in golf)
  • break-hedge (a trespasser)
  • break-league (a treaty breaker)
  • break-love (a disturber of love)
  • break-net (a dogfish)
  • break-peace
  • break-pulpit (a break-pulpit preacher)
  • break-vow
  • breakwind
  • Yeah, well, if you want to use an obsolete word that takes quite a bit of explaining. Dec 24, 2016 at 18:36
  • I think it's quite self-explanatory! Before I posted this, I heard it in some Shakespeare and it was immediately self-evident. The explanation is trying to give a useful and informative answer, as all answers should be here.
    – Hugo
    Dec 24, 2016 at 18:51

A more formal version of OP's suggested word Piker is Defaulter



adj. Unfaithful or disloyal to a belief, duty, or cause: "Consider the man who stands by his duty and goes to the stake rather than be recreant to it" (Mark Twain).

n. A faithless or disloyal person.

[Middle English recreaunt, defeated, from Old French recreant, present participle of recroire, to yield in a trial by combat, surrender allegiance, from Medieval Latin recrēdere, to yield, pledge : Latin re-, re- + Latin crēdere, to believe; see kerd- in Indo-European roots.]American Heritage® Dictionary


n. A disloyal person who betrays or deserts their cause or religion or political party or friend etc.

adj. Not faithful to religion or party or cause WordNet 3.0, Farlex


Let me add forsworn. Which is one of those words with two opposite senses, as "He forswore alcohol," with the sense of making the promise followed by "He went on a drunken bender and was forsworn."


Faithless is one possibility. From Wiktionary:

  1. Not observant of promises or covenants.

Unfaithful or perfidious may be possibilities as well.


I call someone who breaks a promise to me a betrayer. But "reneger" is probably a better choice.

  • Betrayal is too strong a word unless the promise was something very important and personal; Brian said nothing to indicate that the offending person would necessarily have broken so important a trust.
    – itsbruce
    Aug 16, 2013 at 18:53

If it's just in the area of love, it could be 'heart-breaker'.

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