Curl up Definition 1 of 3Pro Tip 1/3Physical Comfort Used to express the feeling of physical coziness, often associated with warmth and relaxation. The cat loves to curl up by the fireplace. Pro Tip 2/3Solo Activity Suggests the person is alone, enjoying their own company with an activity like reading. She's going to curl up with her favorite novel tonight. Pro Tip 3/3Emotional Safety May imply seeking comfort or safety in a protective posture during stress. During the thunderstorm, the child curled up in his bed.