misfire
To fail to work or happen the way it was planned.
To misfire means to fail to work or happen in the intended way. When a gun misfires, it doesn't shoot when the trigger is pulled. When an engine misfires, one of its cylinders fails to ignite properly, causing the car to sputter and lose power.
The word often describes plans or attempts that go wrong. A joke misfires when nobody laughs, leaving awkward silence instead of the laughter you expected. A surprise party misfires when the guest of honor arrives early and walks in on everyone still setting up. A military operation misfires when the timing goes wrong and troops arrive at different times instead of together.
Sometimes misfires are minor annoyances, like when you try to impress someone with a fun fact but get the details wrong. Other times they're more serious, like when a spacecraft's engines misfire during launch. The key is that something was supposed to work a certain way but didn't, often at exactly the wrong moment. A well-planned idea that misfires can feel more frustrating than no plan at all.