A fraction is a part of a whole, especially a small one, or a number like ¾. A faction is a group within a larger group that holds its own views. A fraction of the cost; a faction within the party. The r is the whole difference on the page; breaking versus making is the difference underneath.
The core difference
- fraction — a part of a whole; a number expressing one quantity as part of another. A fraction of a second, only a fraction survived, improper fractions.
- faction — a dissenting group inside a party, organisation or movement. Rival factions, the hard-line faction, factional infighting.
The tell
Fraction has the r of fracture — a broken-off piece. Faction has no r and sits with fact and factory — something made, a group that acts together. A fraction of the party is just some of its members; a faction of the party is an organised bloc with its own line.
In use
- fraction — Only a fraction of the budget was spent. Reduce the fraction to its lowest terms.
- faction — A breakaway faction formed its own party. The two factions could not agree a leader.
Common slips
- only a faction of the cost → only a fraction of the cost
- a fraction inside the party (meaning a bloc) → a faction inside the party
Fraction fractures; faction acts.
Where the words come from
Fraction is from Latin fractio, "a breaking", from frangere "to break" — the same root as fracture and fragile. Faction is from Latin factio, "a making, a party of people", from facere "to do, to make" — originally the chariot-racing teams of Rome, then any organised party.
Frequently asked questions
Is it "a fraction of the cost" or "a faction"?
A fraction — a small part. A faction is a group.
What is a political faction?
An organised group within a party or movement that pursues its own line. The adjective is factional.
Are fraction and fracture related?
Yes — both from Latin frangere, to break. A fraction is a broken-off part.