Other forms: fractions
A fraction is a number written as one number over another: one half, three quarters, seven eighths. It is what you get when a whole thing is cut into equal parts and you count some of them — half a pizza, three quarters of an hour.
Outside maths, a fraction is any tiny amount: a fraction of the cost, a fraction of a second, only a fraction of the crowd stayed to the end. Used that way it always means small, so 'a large fraction' jars on the ear even though the arithmetic allows it. The adjective is fractional and the adverb fractionally: the car is fractionally faster. Chemists have their own sense, where a fraction is one of the parts that separate out when a liquid is distilled — hence fractional distillation at an oil refinery. Do not mix fraction up with faction, which is a small group inside a party.
1nounfractionA number that expresses a part of a whole, written as one number over another.
“The children learned to add fractions with different denominators.”
2nounsmallA very small part or amount of something.
“They bought the table for a fraction of its original price.”
3nounseparatedOne of the parts separated out of a mixture by distillation.
“The lighter fractions boil off first.”
fraction is a number.
Fraction comes from Latin fractio, 'a breaking into pieces', from frangere, 'to break'. It reached English through Old French fraccion as Middle English fraccioun, which meant simply a breaking — so a fraction is a whole thing broken up. Further back stands the Proto-Indo-European root *bhreg-, which travelled into English by a completely different road as the word break.
Proto-Indo-European
*bʰreg-
Middle English
fraccioun
English, today
fraction
Built from
From Middle English fraccioun. From Middle English fraccioun (“a breaking”), from Anglo-Norman -, Old French fraccion, from Medieval Latin fractio (“a fragment, portion”), from earlier Latin fractio (“a breaking, a breaking into pieces”), from fractus, past participle of frangere (“to break”) (whence English frangible), from Proto-Indo-European bʰreg- (English break). a doublet of frazione.
Etymology from Wiktionary, CC BY-SA