To see or observe something, especially something that is difficult to see or that one has been looking for. The birdwatchers were thrilled to sight a rare species of eagle in the forest.
To take aim by aligning the sights of a firearm or other device. The hunter carefully sighted his rifle before taking the shot.
To adjust the sights of a firearm or other device to ensure accuracy. The marksman spent several minutes sighting his rifle at the shooting range.