decimal

UK: /ˈdɛsɪm^əl/ US: /ˈdɛsəməl, ˈdɛsməl/ ,(des′ə məl, des′məl)

WordReference Random House Learner's Dictionary of American English © 2025

dec•i•mal /ˈdɛsəməl, ˈdɛsməl/   adj. [before a noun]

1. Mathematics of or relating to tenths or to the number 10.
2. Mathematics proceeding by tens:
   a decimal system.

n. [countable]

3. Mathematics decimal fraction.

See -dec-.

WordReference Random House Unabridged Dictionary of American English © 2025

dec•i•mal  (des′ə məl, des′məl), adj. 

1. Mathematics pertaining to tenths or to the number 10.
2. Mathematics proceeding by tens:
   a decimal system.

n. 

3. Mathematics See decimal fraction. 

• Medieval Latin decimālis of tenths, equivalent. to Latin decim(a) tenth (derivative of decem ten) + -ālis -al¹
• 1600–10

dec′i•mal•ly, adv. 

Collins Concise English Dictionary © HarperCollins Publishers::

decimal / 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

adjective

1. relating to or using powers of ten
2. of the base ten
3. (prenominal) expressed as a decimal

Etymology: 17th Century: from Medieval Latin decimālis of tithes, from Latin decima a tenth, from decem ten

ˈdecimally adverb