Definition of decimal in English:
decimal
Syllabification: dec·i·malPronunciation: /ˈdes(ə)məl
/
adjective
 1Relating to or denoting a system of numbers and arithmetic based on the number ten, tenth parts, and powers of ten: decimal arithmeticMore example sentences
 The advent of decimal arithmetic reduced the need for such tests.
 The number system which was used to express this numerical information was based on the decimal system and was both additive and multiplicative in nature.
 The discovery of the binomial theorem for integer exponents by alKaraji was a major factor in the development of numerical analysis based on the decimal system.
 1.1Relating to or denoting a system of currency, weights and measures, or other units in which the smaller units are related to the principal units as powers of ten: decimal coinageMore example sentences
 The uniformity of administrative structures was reflected, later, in the imposition of a national, decimal system of weights, measures, and currency.
 Elaborated between 1790 and 1799, the decimal metric system of weights and measures was zealously promoted under Napoleon.
 Even if your business cannot join the general changeover to decimal money for a while after Decimal Day  February 15you still need to prepare now for the introduction of decimal currency.
noun
(also decimal fraction) Back to top 1A fraction whose denominator is a power of ten and whose numerator is expressed by figures placed to the right of a decimal point.More example sentences
 We can use arithmetics with different bases, fractions, decimals, logarithms, powers, or simply words.
 How do you convert decimals and percentages to fractions?
 Basic means a level that really does not exceed primary school: fractions, decimals, percentages and ratios.
 1.1The system of decimal numerical notation.More example sentences
 The same must well have been true of changing our monetary system to decimal.
 In addition to binary and decimal, computers can also speak in octal and hex.
 Though the entries of the table are in decimal, notation along the rows and columns is in hexadecimal.
Derivatives

decimally
adverb
 More example sentences
 Metric units are related decimally.
 He also suggested a standard linear measurement, which he called the mille, based on the length of the arc of one degree of longitude on the Earth's surface and divided decimally.
 The infantry were organized decimally in units of a thousand, with a company and section structure under designated officers.
Origin
early 17th century: from modern Latin decimalis (adjective), from Latin decimus 'tenth'.