abacus

noun

aba·​cus ˈa-bə-kəs  ə-ˈba- 

plural abaci ˈa-bə-ˌsī 

-ˌkē;

ə-ˈba-ˌkī  or abacuses

1

: an instrument for performing calculations by sliding counters along rods or in grooves

2

: a slab that forms the uppermost member or division of the capital of a column

Illustration of abacus

• abacus 1

Did you know?

Probably of Babylonian origin, an abacus is a calculating instrument that uses beads that slide along a series of wires or rods set in a frame to represent the decimal places. It is the ancestor of the modern digital calculator. Used by merchants in the Middle Ages throughout Europe and the Arabic world, it was gradually replaced by arithmetic based on Hindu-Arabic numerals. Though rarely used in Europe past the 18th century, it is still used in the Middle East, China, and Japan.

Examples of abacus in a Sentence

Recent Examples on the Web

Tallied with a fancy algorithm or an abacus, the revenue disparity is substantial: $16.3 million per year for each Bay Area school, on average. —Jon Wilner, The Mercury News, 1 Aug. 2024

The Big Idea: Wearables Get Buzzy Wearable technology dates back to the abacus rings of 17th-century China, early precursors to the modern digital iteration, the calculator watch, released by Pulsar in 1975. —Josh Condon, Robb Report, 13 June 2024

All activities on the board, including counting flaps and an abacus, are made of pinewood and metal, which combine beautifully into an aesthetically pleasing design. —Maya Polton, Parents, 8 Mar. 2024

Who could possibly object to the celebration of calligraphy and glassblowing, of dragon boats, abacus calculation, and mariachi? —Julian Lucas, The New Yorker, 2 Mar. 2024

Word History

Etymology

Latin, from Greek abak-, abax, literally, slab

First Known Use

14th century, in the meaning defined at sense 1

Kids Definition

abacus

noun

aba·​cus ˈab-ə-kəs  ə-ˈbak-əs 

plural abaci ˈab-ə-sī  -ˌkē 

ə-ˈbak-ˌī

or abacuses

: an instrument for making calculations by sliding counters along rods or in grooves