Imprecise means not exact or accurate. When something is imprecise, it's vague, fuzzy, or just a bit off from the true facts.

If you tell someone you'll meet them “sometime after lunch,” that's an imprecise time. They won't know if you mean 12:30 or 3:00. If you measure a table with a ruler and estimate it's “about three feet,” that's imprecise compared to measuring it carefully and finding it's exactly 36 inches.

Scientists and engineers work hard to avoid imprecise measurements because small errors can lead to big problems. An imprecise calculation might cause a bridge to wobble or a rocket to miss its target. In everyday life, though, being imprecise isn't always bad. If someone asks how your day was, “pretty good” is an imprecise but perfectly fine answer.

The opposite of imprecise is precise, which means exact and carefully accurate. Imprecise language can cause confusion: if you give someone imprecise directions to your house, they might get lost. But sometimes precision doesn't matter much, like when you're describing roughly how many people showed up to the school play.