vigesimal
nounEtymology From Latin vīgēsimus (“twentieth”), variant of Latin vīcēsimus (“twentieth”), from Latin vīgintī (“twenty”), (from *vīcēnssos, from Proto-Indo-European *wi(h₁)ḱm̥ttós, with the -imus ending of decimus (“tenth”)) + -al (suffix forming an adjective). Compare Latin vīgintī (“twenty”), from Proto-Indo-European *h₁wih₁ḱm̥ti, from *dwi(h₁)dḱm̥ti(h₁), *dwi(h₁)dḱm̥ti (“two tens; two decades”).
A twentieth part.
- If the years of the incomplete century be divided into twenties, and the excess of twenties resolved into fours, the Dominical Letter will advance three places for every twenty, two places for every four, and six places for every unit of the still outstanding remainder. Hence the Sunday Letter will be found by taking the sum of four numbers, which may be called the centurial, the vigesimal, the quaternial, and the residual.1872, Frederick A[ugustus] P[orter] Barnard, How to Find the Church Festivals without Tables; Being a Letter Addressed to the Chairman of the Committee of the Prayer Book in the House of Clerical and Lay Deputies of the General Convention of the Church, in 1871, Hartford, Conn.: The Church Press; M. H. Mallory and Company, →OCLC, page 4:
- [column 1] The author of this article has also designed an instrumental contrivance for finding Easter by inspection, for any year from the beginning of the Christian era down to the end of hundredth century, in old style or new. […] [column 2] Around the fixed ring here described is a rotary ring bearing the numbers from 1 to 19 (the golden numbers) twice repeated, and at the left of these the vigesimals, arranged in regular order.1876, F[rederick] A[ugustus] P[orter] Barnard, “Easter”, in Frederick A. P. Barnard, Arnold Guyot, editors, Johnson’s New Universal Cyclopædia: A Scientific and Popular Treasury of Useful Knowledge. [...], volumes I (A–E), New York, N.Y.: A[lvin] J[ewett] Johnson & Son, 11 Great Jones Street, New York; Pittsburg, Pa.: W. D. Cummings; San Francisco, Calif.: H. D. Watson, →OCLC, page 1463, columns 1–2:
2 more examples
- They had all attended an abacus school (scuola d'abaco), where the basic training program, well known from the numerous practical treatises on the subject that survive, had taught them above all how to deal in different moneys and to make the four basic arithmetic calculations, using what for them was the standard mensural system based on vigesimals and duodecimals.2009, Richard A. Goldthwaite, “The Network”, in The Economy of Renaissance Florence, Baltimore, Md.: Johns Hopkins University Press, →ISBN, page 83:
- The Yoruba series of number names generates primarily around a base of twenty. […] The core process in the working of the system is progression from one vigesimal (twenty) point to the next. Multiplication generates multiples of ogún (twenty), or to be more exact, "multiple placing out," as the Yoruba verb embedded in the numeral has it. About the vigesimals, intermediate numerals are generated using tens and fives.2010, Helen Verran, “Yorub and English Number Systems”, in Science and an African Logic, Chicago, Ill.: University of Chicago Press, →ISBN, page 55:
“vigesimal”, in Merriam-Webster.com Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.
“vigesimal”, in OED Online , Oxford: Oxford University Press, launched 2000.
“vigesimal”, in The American Heritage Dictionary of the English Language, 5th edition, Boston, Mass.: Houghton Mifflin Harcourt, 2016, →ISBN.