Catnap/ˈkætnæp/ Definition 1 of 2Pro Tip 1/3Short Rest A catnap implies a very brief period of sleep, usually lasting 15 to 30 minutes. I grabbed a quick catnap before my meeting. Pro Tip 2/3Energizing Effect The word often suggests that the sleep is refreshing and revitalizes the person. Feeling drowsy, I took a catnap and woke up invigorated. Pro Tip 3/3Daytime Sleep It refers specifically to napping during the day, not at night. After working all morning, she had a catnap in the sunshine.