A nap taken any time of the day, whether morning, afternoon, or evening. It is refreshing & reinvigorating. A Niknap will not affect your ability to sleep at night. Everyone should take a daily Niknap.
The act of taking a nap while resting your head on the bounteous bosoms of your girlfriend, wife, chick you met in line at the bank, etc., occasionally awakening to suck on those lovely nipples while murmuring "Mama." Usually post-coital, but need not be.