the reformed Julian calendar now in use, according to which the ordinary year consists of 365 days, and a leap year of 366 days occurs in every year whose number is exactly divisible by 4 except centenary years whose numbers are not exactly divisible by 400, as 1700, 1800, and 1900.
the revision of the Julian calendar introduced in 1582 by Pope Gregory XIII and still in force, whereby the ordinary year is made to consist of 365 days and a leap year occurs in every year whose number is divisible by four, except those centenary years, such as 1900, whose numbers are not divisible by 400
noun 1. the plain song or cantus firmus used in the ritual of the Roman Catholic Church. 2. a melody in this style. noun 1. another name for plainsong The traditional music for Latin texts in the worship of the Roman Catholic Church. Gregorian chant is marked by performance in unison and by free-flowing rhythms […]
noun, Music. 1. .
noun 1. a telescope similar in design to the Cassegrainian telescope but less widely used. noun 1. a form of reflecting astronomical telescope with a concave ellipsoidal secondary mirror and the eyepiece set behind the centre of the parabolic primary mirror
- Gregorian tone
noun 1. a plainsong melody See tone (sense 6)