Squirrel/ˈskwɜːrəl/ Definition 1 of 2Pro Tip 1/3Animal Species Relates specifically to the various species of small tree-dwelling rodents. The eastern gray squirrel is native to North America. Pro Tip 2/3Idiomatic Use Used metaphorically to describe someone who is active or jumpy. My little cousin is as energetic as a squirrel. Pro Tip 3/3Descriptive Imagery Evokes a vivid picture of the animal's playful nature and agility. Watching a squirrel dart around the park is entertaining.