aba·​cus | \ ˈa-bə-kəs How to pronounce abacus (audio) , ə-ˈba- How to pronounce abacus (audio) \
plural abaci\ ˈa-​bə-​ˌsī How to pronounce abaci (audio) , -​ˌkē ; ə-​ˈba-​ˌkī How to pronounce abaci (audio) \ or abacuses

Definition of abacus

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

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.

First Known Use of abacus

14th century, in the meaning defined at sense 1

History and Etymology for abacus

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

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Dictionary Entries near abacus


a baculo




a bad crowd


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Time Traveler for abacus

The first known use of abacus was in the 14th century

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Financial Definition of abacus

What It Is

An abacus is a counting device that performs basic mathematical functions.

How It Works

The abacus is believed to have been developed in the ancient Near East in the third millennium BCE. An abacus consists of a series of thin parallel bars set into a rectangular frame, usually made of wood. Each bar contains a number of beads that slide along its length. Individuals use the beads as number counters and use the abacus to perform addition, subtraction, multiplication, and division.

Why It Matters

The abacus has been in continuous use since its conception. It is still widely used in Far Eastern cultures including China and Japan.

Source: Investing Answers



English Language Learners Definition of abacus

: a device used for counting and calculating by sliding small balls or beads along rods or in grooves


aba·​cus | \ ˈa-bə-kəs How to pronounce abacus (audio) \
plural abaci\ ˈa-​bə-​ˌsī \ or abacuses

Kids Definition of abacus

: an instrument for doing arithmetic by sliding counters along rods or in grooves

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More from Merriam-Webster on abacus

Spanish Central: Translation of abacus

Nglish: Translation of abacus for Spanish Speakers

Britannica English: Translation of abacus for Arabic Speakers

Britannica.com: Encyclopedia article about abacus

Comments on abacus

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something desired as essential

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