寝しん衣いしんいMeanings1nounnightclothes; sleepwearA somewhat formal or written term for nightclothes; in everyday speech, 寝巻き (ねまき) is more common.See also: 寝巻き旅りょ館かんでは寝しん衣いが用よう意いされていた。Nightclothes were provided at the inn.