ETYM French fraction, Latin fractio a breaking, from frangere, fractum, to break. Related to Break.
1. A component of a mixture that has been separated by a fractional process.
2. A small piece or item forming part of a whole.
3. The quotient of two rational numbers.

In chemistry, a group of similar compounds, the boiling points of which fall within a particular range and which are separated during fractional distillation (fractionation).

In mathematics, a number that indicates one or more equal parts of a whole. Usually, the number of equal parts into which the unit is divided (denominator) is written below a horizontal line, and the number of parts comprising the fraction (numerator) is written above; thus 2/3 or ľ. Such fractions are called vulgar or simple fractions. The denominator can never be zero.
A proper fraction is one in which the numerator is less than the denominator. An improper fraction has a numerator that is larger than the denominator, for example 3/2. It can therefore be expressed as a mixed number, for example, 1˝. A combination such as 5/0 is not regarded as a fraction (an object cannot be divided into zero equal parts), and mathematically any number divided by 0 is equal to infinity. A decimal fraction has as its denominator a power of 10, and these are omitted by use of the decimal point and notation, for example 0.04, which is 4/100. The digits to the right of the decimal point indicate the numerators of vulgar fractions whose denominators are 10, 100, 1,000, and so on. Most fractions can be expressed exactly as decimal fractions (1/3 = 0.333.). Fractions are also known as the rational numbers, that is numbers formed by a ratio. Integers may be expressed as fractions with a denominator of 1.