Excavation is the process of carefully digging up earth, rocks, or other materials to uncover what lies beneath the surface. When construction workers dig a deep hole for a building's foundation, they're doing excavation work. When archaeologists slowly brush away dirt to reveal ancient pottery or dinosaur bones, that's excavation too.

Sometimes excavation means removing tons of soil with massive machinery, like when building a subway tunnel or mining for minerals. Other times it requires tiny brushes and patient, precise work, like when paleontologists spend weeks excavating a single fossil from stone.

An excavation site is the specific location being dug up. You might read about an excavation in Egypt where archaeologists discovered a pharaoh's tomb, or see an excavation in your neighborhood where workers are installing new water pipes.

The verb form is excavate. Scientists excavate carefully to preserve whatever they find. The noun excavator can mean either a person who digs or the large machine with a huge scoop that construction crews use for big digging jobs.