Guesswork is the process of figuring something out without having complete information or certainty. When you use guesswork, you're making your best estimate based on whatever clues or knowledge you have, even though you can't be sure you're right.

A detective might solve a case through careful investigation and evidence, but if they have to rely on guesswork, they're filling in missing pieces with educated assumptions. A student who didn't study for a multiple-choice test might resort to guesswork, picking answers based on hunches rather than actual knowledge. A doctor who doesn't have all the test results yet might begin with some guesswork about what's making a patient sick, then confirm or correct those guesses with more information.

The word often suggests that a more reliable method would be better if available. Scientists try to eliminate guesswork by doing careful experiments. Engineers measure precisely rather than relying on guesswork. But sometimes guesswork is unavoidable: when you're planning an outdoor party, there's always some guesswork involved in predicting the weather.

Notice that guesswork isn't always wild or random. An experienced carpenter's guesswork about a measurement might be remarkably accurate because they've done similar work hundreds of times before.