nighttime

Etymology

From Middle English nyght tyme, nyȝttyme, equivalent to night + time. Compare Dutch nachttijd, German Nachtzeit, Danish nattetid, Swedish nattetid. Compare also Middle English nyȝter tyme (“nighttime”), from Old Norse náttartími, nætrtími (“nighttime”).

noun

1. The hours of darkness between sunset and sunrise; the night.
   Smith Barney, for example, goes so far as to shift the hours during which taxi rides home are expensable as nighttime lengthens and shortens, says Moszkowski. 1996, Kiplinger's Personal Finance, volume 50, number 7, page 52

adj

1. Pertaining to nighttime; appropriate to the night.
2. Happening during the night.