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

Keep scrolling for more

Learn More about abacus

Time Traveler for abacus

Time Traveler

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

See more words from the same century

Statistics for abacus

Last Updated

31 Oct 2019

Cite this Entry

“Abacus.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., https://www.merriam-webster.com/dictionary/abacuses. Accessed 15 December 2019.

Keep scrolling for more

More Definitions for abacus



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


How to pronounce abacus (audio) How to pronounce abacus (audio)

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

Keep scrolling for more

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

What made you want to look up abacus? Please tell us where you read or heard it (including the quote, if possible).


delight or enjoyment

Get Word of the Day daily email!

Test Your Vocabulary

Great Scrabble Words—A Quiz

  • scrabble tiles that read scrabble quiz
  • Which of the following Q-without-U words means the number five in cards or dice?
Spell It

Can you spell these 10 commonly misspelled words?

Syn City

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!