Dictionary entry

Lunation

Webster's Dictionary 1913

Lu‐na″tion (?), n. [Cf. Lunated.] The period of a synodic revolution of the moon, or the time from one new moon to the next; varying in length, at different times, from about 29¼ to 29⅚ days, the average length being 29 d., 12h., 44m., 2.9s.