abacus

From Latin abacus, abax; from Ancient Greek ἄβαξ (ábax, “board covered with sand”), possibly from a Semitic source; compare Hebrew אבק‎ (āvāq, “dust”).

• (Received Pronunciation) IPA^(key): /ˈæb.ə.kəs/, /əˈbæk.əs/, rarely IPA^(key): /əˈbɑk.əs/
• (General American) IPA^(key): /ˈæb.ə.kəs/, /əˈbæk.əs/, rarely IPA^(key): /əˈbɑk.əs/

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abacus (plural abaci or abacuses)

1. (obsolete) A table or tray strewn with sand, anciently used for drawing, calculating, etc. [Attested from around 1350 (1387) until around 1470.][1]
2. A calculating table or frame; an instrument for performing arithmetical calculations by balls sliding on wires, or counters in grooves, the lowest line representing units, the second line, tens, etc. [First attested in the late 17^th century.][2]

   I've heard merchants still use an abacus for adding things up in China.

   • 1888, Walter William Rouse Ball, A Short Account of the History of Mathematics, page 119:

     The abacus is obviously only a concrete way of representing a number in the decimal system of notation, that is, by means of the local value of the digits.

   • 1888, Walter William Rouse Ball, A Short Account of the History of Mathematics, page 123:

     We may there find some slight attempts at a study of literature, but mathematics was never read: to learn the use of the abacus, to keep accounts, and to know the rule by which the date of Easter could be determined was all the science that the most studious aimed at.

   • 2008, Valerie Anand, The House of Lanyon, page 55:

     She's handy with a loom and an abacus, as well.

   • 2008, Valerie Anand, The House of Lanyon, page 209:

     She was sitting at the parlour table with a small abacus in front of her.

3. (architecture) The uppermost portion of the capital of a column, immediately under the architrave. [First attested in the mid 16^th century.][2]
   • 2005, The Classical Orders of Architecture, 2nd edition, page 76:

     The abacus is moulded in three sections and has four main concave faces corresponding with the tapering volutes below and truncated by a short sqaure face on the diagonal.

4. A board, tray, or table, divided into perforated compartments, for holding cups, bottles, or the like; a kind of cupboard, buffet, or sideboard. [First attested in the late 18^th century.][2]

• abacus in Webster’s Revised Unabridged Dictionary, G. & C. Merriam, 1913.

• “abacus” in Douglas Harper, Online Etymology Dictionary, 2001–2019.

• abax

From Ancient Greek ἄβαξ (ábax, “board”)

• (Classical) IPA^(key): /ˈa.ba.kus/, [ˈa.ba.kʊs]

abacus m (genitive abacī); second declension

1. a square board
2. sideboard
   • 70 BCE, Cicero, In Verrem II.4.35:

     Ab hoc abaci vasa omnia, ut exposita fuerunt, abstulit.

     From this place he removed all the sideboard's dishes, since they had been exposed.

3. counting board, abacus.
   • c. 62 CE, Persius, Saturae I.131:

     ...nec qui abaco numeros et secto in pulvere metas / scit risisse vafer, multum gaudere paratus, / si cynico barbam petulans nonaria vellat.

     ...nor the man who has the wit to laugh at the figures on the counting board and the cones drawn in sand, ready to go off in ecstasies if a prostitute pulls a Cynic by the beard.

4. gaming board.
   • 121 CE, Suetonius, De vita Caesarum Neronis.XXII.1:

     Sed cum inter initia imperii eburneis quadrigis cotidie in abaco luderet, ad omnis etiam minimos circenses e secessu commeabat, primo clam, deinde propalam, ut nemini dubium esset eo die utique affuturum.

     But in the early stages of his rule he used to play every day on a gaming board with ivory chariots. He would also travel from his retreat to the Circus games, even the least important ones, at first in secret and then openly. As a result, no one was in any doubt that he would be present in Rome that day at least.

5. a painted ceiling or wall panel.
   • c. 77 CE – 79 CE, Pliny the Elder, Naturalis Historia XXXIII.56:

     Hoc autem et Attico ad lumina utuntur, ad abacos non nisi marmoroso, quoniam marmor in eo resistit amaritudini calcis.

     This and the Attic sort they used for high lights, for panels none but the marmorean kind, because the marble in it resists acridity of the lime.

6. a panel
7. a tray

Second declension.

• ăbăcus in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
• abacus in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
• abacus in Charles du Fresne du Cange’s Glossarium Mediæ et Infimæ Latinitatis (augmented edition, 1883–1887)
• abacus in Gaffiot, Félix (1934) Dictionnaire Illustré Latin-Français, Hachette
• abacus in The Perseus Project (1999) Perseus Encyclopedia‎
• abacus in Harry Thurston Peck, editor (1898) Harper's Dictionary of Classical Antiquities, New York: Harper & Brothers
• abacus in William Smith et al., editor (1890) A Dictionary of Greek and Roman Antiquities, London: William Wayte. G. E. Marindin
• Professor Kidd, et al. Collins Gem Latin Dictionary. HarperCollins Publishers (Glasgow: 2004). →ISBN. page 1.