Noah Webster's Dictionary 1. (a.) Pertaining to the night; as, nocturnal darkness, cries, expedition; -- opposed to diurnal. 2. (a.) Having a habit of seeking food or moving about at night; as, nocturnal birds and insects. 3. (n.) An instrument formerly used for taking the altitude of the stars, etc., at sea.

Multi-Version Concordance Nocturnal (1 Occurrence) Deuteronomy 23:10 If there is among you any man who is not clean by reason of that which happens him by night, then shall he go outside of the camp. He shall not come within the camp: (See NAS NIV)