decimal

American  

[des-uh-muhl, des-muhl] / ˈdɛs ə məl, ˈdɛs məl /

adjective

1. pertaining to tenths or to the number 10.

2. proceeding by tens.

   a decimal system.

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noun

1. decimal fraction.

decimal British  

/ ˈdɛsɪməl /

noun

1. Also called: decimal fraction.  a fraction that has a denominator of a power of ten, the power depending on or deciding the decimal place. It is indicated by a decimal point to the left of the numerator, the denominator being omitted. Zeros are inserted between the point and the numerator, if necessary, to obtain the correct decimal place

2. any number used in the decimal system

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adjective

1. 1. relating to or using powers of ten

   2. of the base ten

2. (prenominal) expressed as a decimal

decimal Scientific  

/ dĕs′ə-məl /

1. A representation of a real number using the base ten and decimal notation, such as 201.4, 3.89, or 0.0006.

2. A decimal fraction.

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Other Word Forms

• decimally adverb

Etymology

Origin of decimal

First recorded in 1600–10; from Medieval Latin decimālis “of tenths,” equivalent to Latin decim(a) “tenth” (derivative of decem “ten” ) + -ālis adjective suffix; ten, -al ¹

Explanation

A decimal is a fraction written in a special form. Instead of writing 1/2, for example, you can express the fraction as the decimal 0.5, where the zero is in the ones place and the five is in the tenths place. Decimal comes from the Latin word decimus, meaning tenth, from the root word decem, or 10. The decimal system, therefore, has 10 as its base and is sometimes called a base-10 system. Decimal can also specifically refer to a number in the decimal system. As an adjective, decimal means something related to this numbering system. The decimal point, for example, refers to the period that separates the ones place from the tenths place in decimal numbers.

Example Sentences

“My usual rule of thumb is, move the decimal point one place to the left,” Matheson said.

From Los Angeles Times • Feb. 24, 2026

That little decimal point wasn’t a lot, but then, artificial intelligence was barely a decimal point’s worth of those index funds a few years ago.

From Slate • Feb. 3, 2026

In recent decades, advances in computing have pushed this familiar constant far beyond the classroom, with powerful supercomputers now calculating pi to trillions of decimal places.

From Science Daily • Dec. 16, 2025

In July 2024, Nature issued a correction noting that rows of data were “wrongly printed as a decimal, rather than a percentage point.”

From The Wall Street Journal • Dec. 9, 2025

Everybody was headed to the second floor and the Dewey decimal rooms.

From "Escape from Mr. Lemoncello's Library" by Chris Grabenstein

Related Words

• figure
• statistic
• sum
• total