A sheep is a four-legged farm animal with a thick, wooly coat. Sheep are raised for this wool, as well as for meat, and they're known for their habit of staying close together in a flock.
If you have a big flock of sheep, you might want to consider a herding dog or two to keep them in line. Have trouble falling asleep? Try counting sheep, a time-honored method of visualizing one sheep after another jumping over a fence, until you drift off. Sheep can also be used to describe people who never act independently and simply follow the crowd.