Word Finder
What's the word for someone who never keeps their promises?
The word you're looking for
Someone who cannot be depended on to do what they say; they frequently fail to keep their promises or commitments. This is the most common word for describing this behavior at intermediate English level.
Other words that fit
More formal than unreliable; emphasizes that you cannot trust this person's character or judgment, not just their follow-through.
Suggests someone changes their mind frequently or their feelings are inconsistent; less about deliberate betrayal, more about lack of constancy.
Very formal or literary; means deliberately treacherous or disloyal, suggesting intentional betrayal rather than simple failure to deliver.
Why this word
Unreliable is the everyday English word for someone who doesn't keep their promises. It simply means you cannot depend on this person to do what they say they will do. The word focuses on behavior and action rather than judging someone's character as deeply dishonest. You might use unreliable for someone who constantly cancels plans, misses deadlines, or forgets commitments—whether by accident or laziness. Untrustworthy is similar but slightly more formal and suggests a character flaw. Fickle implies someone changes their mind easily, often about preferences or loyalties. Perfidious, the most formal option, suggests intentional betrayal and appears mainly in literary or academic writing.
In context
- He promised to call, but he never did. He's so unreliable.
- I can't ask her for help anymore because she's been unreliable in the past.
- My coworker is unreliable; deadlines mean nothing to him.
Other concepts to find a word for
Frequently asked questions
- Is 'unreliable' the same as 'dishonest'?
- Not exactly. Unreliable means someone fails to keep their word or do what they promise, but it doesn't necessarily mean they're lying intentionally. Dishonest means deliberately telling lies or deceiving someone.
- When should I use 'untrustworthy' instead of 'unreliable'?
- Use untrustworthy when you want to question someone's overall character or judgment. Use unreliable when specifically describing their failure to follow through on promises or tasks.
- Can I describe a broken promise using just 'unreliable'?
- Yes. For example: 'He made an unreliable promise' or 'She has a reputation for being unreliable about keeping commitments.'
- Is there a noun form of unreliable?
- Yes—the noun is unreliability. Example: 'His unreliability was frustrating for everyone who depended on him.'