I know that renege is a word that could suit in here. But as I understand, 'renege' describes the failure to keep a promise.

But, sometimes, we make promises that we know all too well that it can't be kept for long. Is there any word or a phrase for such promises?.


11 Answers 11


You are describing an empty promise, which is a promise that will not be kept. It doesn't directly describe the timeframe in which the promise is broken, but an empty promise will usually not be fulfilled at all.

  • 10
    This answer should note that “empty promise” focuses on the fact that the promise will not be kept—not that it could not be kept.
    – KRyan
    Commented Aug 26, 2021 at 14:38
  • 4
    Agreed with KRyan. "Empty promise" has a connotation where it was made when the maker has no intention or expectation to fulfill the promise, whereas the question is regarding a promise made when the maker is unable to fulfill it. A subtle but important distinction.
    – Abion47
    Commented Aug 26, 2021 at 19:54
  • @Abion47 IMO it fits here. If you knowingly make a promise you cannot keep, it's an empty promise. Especially in the context of "cannot keep it for long", that suggests it's too difficult to choose to keep it, not that it's literally impossible.
    – Kat
    Commented Aug 28, 2021 at 15:27

In the movie Mary Poppins, Mary refers to such promises as "Pie crust promises". "Easily made, easily broken".

Michael: Will you stay if we promise to be good?

Mary Poppins: Och! That's a piecrust promise. Easily made, easily broken.

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    Not a lot of tokens on Google, but too good to downvote. Commented Aug 26, 2021 at 11:20

false promise

A promise that is made with no intention of carrying it out and especially with intent to deceive or defraud m-w

Now it might be said that the moral rigorism involved in the view that we ought never, in any circumstances, to make false promises, tell lies or break promises is just a personal idiosyncrasy of Kant's, and that we do not have to treat it as an integral part of his moral philosophy...It is one thing to argue that if everyone made false promises whenever they thought it to their advantage there could be no such thing as a promise... ref.

A promise is false, not by virtue of not making promise, but by virtue of not doing the relevant things subsequently. Hence a false promise is a case of a promise. ref.

The gravamen of Ms. Tarmann's complaint was that the defendant insurer made a false promise to pay for car repairs upon their completion a future event. ref.

There is a bad faith promise in law:

A bad faith promise remains an effective promise “but it is not a lie or a misstatement.” ref.

  • I don't think you can separate "bad faith statement" from "lie". They are almost synonyms. If something is done in bad faith, it is a deliberate deception.
    – Kaz
    Commented Aug 26, 2021 at 5:37
  • For all intents and purposes I agree. However, I think there are linguistic and truth-condition nuances. If I make a promise in bad faith, but then keep it (for whatever reason), it may have been made in bad faith, but at least in one sense it wasn't a lie. However, it does meet the requirement: (1) it was made in the form of a promise and (2) there was no intention of keeping it
    – DjinTonic
    Commented Aug 26, 2021 at 9:15
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    This answer has the same problem as "empty promise" where it means the maker has no intention of keeping the promise, not that they couldn't keep the promise.
    – Abion47
    Commented Aug 26, 2021 at 19:55
  • Yes false promises can be that, but others may be disingenuous promises that turn out to be false because they were indeed broken. If I had to write an answer from scratch, disingenuous promises might be a better fit. It also has to do with "can't be kept" -- actual impossibility or likelihood?
    – DjinTonic
    Commented Aug 26, 2021 at 20:33

If you make a promise you know you cannot keep, the word for that is lie.

I'm not entirely satisfied with this because lie is a broader category; not every lie is a promise, other than in the guarantee (a fact) nuance of promise which appears in I promise you that this is true.

However, it's usually clear from context that a reference to some lie is actually about a bad faith promise, rather than some other lie, such as a cover-up of events or failed responsibilities.

I suspect that there might not exist a single verb which we can fill in for

Bob ____ed that he will return the money

where where ____ed specifically means lied as he promised.

However, note that in an example like this we do not need such a verb, because the complement "that he will return the money" establishes the context that a promise is being made, allowing us to just use the verb to lie:

Bob lied that he will return the money.

  • Perhaps a white lie?
    – Tim
    Commented Aug 26, 2021 at 6:44
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    @Tim absolutely not. A white lie is a lie made with good intentions. An intention to break a promise is not a good one.
    – Simon
    Commented Aug 26, 2021 at 7:23
  • @Simon It can still be a white lie. E.g. telling your doctor that you'll improve your diet, to get them to stop bugging you about it. You know that you won't be able to keep it up for long.
    – Barmar
    Commented Aug 26, 2021 at 14:14
  • @Barmar That's not really a promise; it's more like a resolution or pledge made in front of the doctor. Your doctor cares about you professionally, but ultimately knows it's just up to you and doesn't care that way.
    – Kaz
    Commented Aug 26, 2021 at 15:33
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    @Barmar that’s not a white lie. The intention is to deceive your doctor. It doesn’t become a good intention just because it benefits the liar!
    – Simon
    Commented Aug 26, 2021 at 18:25

Somebody who commits or attempts to do something they can't succeed at can be said to have bitten off more than they can chew.

  • I think this is one of those "similar area, which makes it all the more wrong". BOMTYCC generally means there's too much work and you won't be able to finish. The Q seems more like "I'll change the babies diapers" -- you can do it, but definitely won't. Commented Aug 26, 2021 at 5:15
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    This implies that the person who made the promise really wanted to keep it, but couldn't. Not what OP is asking.
    – Tim
    Commented Aug 26, 2021 at 6:42
  • @OwenReynolds The question asks about when a promise is made with the knowledge that it can't be kept. It doesn't make any assumptions on whether the promise was made maliciously or with good intentions.
    – Abion47
    Commented Aug 26, 2021 at 19:49

I don't think it is a standing expression, but instead of the term "impossible promise" which implies that there isn't a point to an attempt of keeping it, a possibly better fit may be "doomed promise" to indicate that it won't likely progress to the state of fulfillment.


I'd probably just go with overcommit / overcommitment.

"To bind or obligate (oneself, for example) beyond the capacity for realization."

It isn't limited by whether or not the committer knew it was unrealizable, only that it was. It could be qualified as "knowingly overcommit" where appropriate.


Variations on don't write a cheque that you can't cash.

Quora, referencing Top Gun.

Stinger (the aircraft carrier commander) tells Maverick, "Son, your ego is writing checks your body can't cash."

Or, Don't write checks your body can't cash

The "mouth/ego" writing part and the "body" cashing part don't matter all that much here. Something writes a cheque, i.e. makes a commitment, and can't cash it, i.e. what was promised could not possibly be delivered.

Urban Dictionary has a more colorful variation on this theme.


There is no single word for "promises that can't be kept". So the next best thing is a phrase:

transient promises

From Dictionary.com:

transient (adjective)

  1. not lasting, enduring, or permanent; transitory.

  2. lasting only a short time; existing briefly; temporary: transient authority.

  3. staying only a short time: the transient guests at a hotel.


False Pretenses:

false pre·​tens·​es | \ -ˈpre-ˌten-səz, -pri-ˈten- \
Legal Definition of false pretenses : false representations concerning past or present facts that are made with the intent to defraud another also : the crime of obtaining title to another's property by false pretenses From Merriam-Webster

This is similar to a false premise, depending on how it is used and the level of culpability. Check out the synonyms if one works better for you. I like "concocted" personally.

  • That's just legalese verbiage. Can there be "true pretenses"? Merriam-Webster also gives one definition of "pretense" as "false appearance or action intended to deceive"; the "false" is built into "pretense". It's pretty much just a synonym of "sham", "deception", and such."The crime of obtaining title to another's property by lying" works just fine.
    – Kaz
    Commented Aug 27, 2021 at 12:02
  • @Kaz I'm not disagreeing, but English is full of this stuff, and it seemed the closest match I could find to "I know it's physically impossible for my lie to ever be true."
    – DWKraus
    Commented Aug 27, 2021 at 12:15

Impossible promises or not possible to keep promises

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    Impossible promise works, not sure about the other. Could you perhaps show an example?
    – mcalex
    Commented Aug 26, 2021 at 7:59

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