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abacus

American  
[ab-uh-kuhs, uh-bak-uhs] / ˈæb ə kəs, əˈbæk əs /

noun

plural

abacuses, abaci
  1. a device for making arithmetic calculations, consisting of a frame set with rods on which balls or beads are moved.

  2. Architecture. a slab forming the top of the capital of a column.


abacus British  
/ ˈæbəkəs /

noun

  1. a counting device that consists of a frame holding rods on which a specific number of beads are free to move. Each rod designates a given denomination, such as units, tens, hundreds, etc, in the decimal system, and each bead represents a digit or a specific number of digits

  2. architect the flat upper part of the capital of a column

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of abacus

1350–1400; Middle English < Latin: board, counting board, re-formed < Greek ábax

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Calculators, cars and probably candles and the abacus were considered a menace to society.

From The Wall Street Journal • Dec. 7, 2025

For example, you can add numbers perfectly using an abacus, in which wooden beads are pushed back and forth to represent arithmetic operations.

From Science Daily • Oct. 30, 2023

She had accused her old department of promoting an "abacus economics" of "making sure that tax and spend add up," saying greater focus was required on promoting economic growth.

From BBC • Oct. 10, 2022

Thus many of her pieces, like earrings with lines of delicately strung freshwater pearls that resemble an abacus, are made entirely in house.

From New York Times • Apr. 14, 2022

Before Arabic numerals came around, money counters had to make do with an abacus or a counting board.

From "Zero: The Biography of a Dangerous Idea" by Charles Seife