napper
A person who takes short sleeps during the day.
A napper is someone who takes naps, those short sleeps during the day when you're not in bed for the night. Some people are regular nappers who rest for twenty minutes after lunch, while others almost never nap at all.
Young children are famous nappers because their bodies need extra rest as they grow. But plenty of adults are nappers too. Some of history's greatest minds, like Thomas Edison and Albert Einstein, were devoted nappers who believed their afternoon rest helped them think more clearly and solve difficult problems.
You might hear someone say “I'm not much of a napper” if they find it hard to fall asleep during the day, or “She's a champion napper” about someone who can doze off anywhere, anytime.
Being a good napper is actually a skill. Some people can nap for fifteen minutes on a bus or in a chair and wake up refreshed, while others feel groggy and confused after a daytime nap. Athletes often become skilled nappers because rest helps their muscles recover between practices and competitions.