quatrevingts

Quatre-vingts is the French word for the number 80. It literally means four twenties and reflects the historical vigesimal influence on French number naming. In standard French, the 70s, 80s, and 90s are formed as soixante-dix (sixty-ten), quatre-vingts, and quatre-vingt-dix (four twenties ten), respectively.

Spelling and usage: When used alone as a cardinal number, quatre-vingts takes an s. When it forms part of a larger number, the final s is typically dropped: quatre-vingt-un, quatre-vingt-deux, quatre-vingt-dix, etc.

Origins and regional variation: The form derives from quatre plus vingt. This vigesimal system was common in older stages of French, with 60 being soixante and 70/90 built as combinations around sixty or four twenties. In modern standard French, quatre-vingts is the prevailing form for 80. Some regional varieties, notably in Swiss French and certain historical Belgian usage, have used octante as an alternative for 80, but octante is uncommon in contemporary standard French.

Examples: 80 = quatre-vingts; 81 = quatre-vingt-un; 85 = quatre-vingt-cinq; 90 = quatre-vingt-dix; 99 = quatre-vingt-dix-neuf.