
1) Christian term
Found on
https://www.crosswordclues.com/clue/computus

Computus (Latin for `computation`) is the calculation of the date of Easter in terms of, first, the Julian and, later, the Gregorian calendar. The name has been used for this procedure since the early Middle Ages, as it was considered the most important computation of the age. Following the First Council of Nicaea, the date for Easter was comple.....
Found on
http://en.wikipedia.org/wiki/Computus

(from the article `mathematics`) For monastic life it sufficed to know how to calculate with Roman numerals. The principal application of arithmetic was a method for determining the ...
Found on
http://www.britannica.com/eb/a-z/c/123

computus 1. A computation, a reckoning; an account. 2. The medieval name for a set of tables for practically calculating astronomical occurrences and the movable dates of the calendar; a calendar.
Found on
http://www.wordinfo.info/words/index/info/view_unit/1803/2
No exact match found.