I. (ˈ)näk|tərn ə l, -tə̄n- adjective
Etymology: Middle French or Late Latin; Middle French nocturnal, nocturnel, from Late Latin nocturnalis, from Latin nocturnus of night, nocturnal + -alis -al; akin to Latin nox night — more at night
1. : of or relating to night : done, held, or occurring in the night
nocturnal darkness
a nocturnal journey
2.
a. : active at night — used of animals and sometimes plants that perform most of their functions (as feeding, breeding, or blooming) at night; compare diurnal
b. : characterized by nocturnal activity
a nocturnal form of filariasis
a nocturnal flower
3. : suggestive of or having the character of a nocturne
4. of a sign of the zodiac : even 5a
• noc·tur·nal·ly - ə lē, - ə li adverb
II. noun
( -s )
1. : night piece ; specifically : a play in which the action takes place to a considerable extent on a darkened stage
2. : one that is abroad or active at night : nightwalker
3. : an astrolabe formerly used for finding the time at night or determining latitude