Gre‧go‧ri‧an cal‧en‧dar /ɡrɪˌɡɔːriən ˈkæləndə $ -dər/ noun [singular]
[Date: 1600-1700; Origin: Because it was introduced by Pope Gregory XIII]
the system of arranging the 365 days of the year in months and giving numbers to the years from the birth of Christ, used in the West since 1582

[TahlilGaran] Dictionary of Contemporary English ▲