Your request was nightap which is probably a typo from nightcap.
nightap -
English Idioms :: nightcap
nightap - {n.} A good-night drink; a drink taken just before bedtime. * /Let's have a nightcap and then go to sleep./ * /Would you like to come up to my place for a nightcap?/
Traditional English :: nightcap
nightap - n. 1 hist. a cap worn in bed. 2 a hot or alcoholic drink taken at bedtime.