Proto-Indo-European root meaning "four."

It forms all or part of: cadre; cahier; carillon; carrefour; catty-cornered; diatessaron; escadrille; farthing; firkin; fortnight; forty; four; fourteen; fourth; quadrant; quadraphonic; quadratic; quadri-; quadrilateral; quadriliteral; quadrille; quadriplegia; quadrivium; quadroon; quadru-; quadruped; quadruple; quadruplicate; quarantine; quarrel (n.2) "square-headed bolt for a crossbow;" quarry (n.2) "open place where rocks are excavated;" quart; quarter; quarterback; quartermaster; quarters; quartet; quarto; quaternary; quatrain; quattrocento; quire (n.1) "set of four folded pages for a book;" squad; square; tessellated; tetra-; tetracycline; tetrad; tetragrammaton; tetrameter; tetrarch; trapezium.

It is the hypothetical source of/evidence for its existence is provided by: Sanskrit catvarah, Avestan čathwaro, Persian čatvar, Greek tessares, Latin quattuor, Oscan petora, Old Church Slavonic četyre, Lithuanian keturi, Old Irish cethir, Welsh pedwar.

early 13c., "rank, standing, condition," from Anglo-French astat, Old French estat "state, position, condition, health, status, legal estate" (13c., Modern French état), from Latin status "state or condition, position, place; social position of the aristocracy," from PIE root *sta- "to stand, make or be firm."

For the unetymological e-, see e-. Sense of "property" is late 14c., from that of "worldly prosperity;" specific application to "landed property" (usually of large extent) is first recorded in American English 1620s. A native word for this was Middle English ethel (Old English æðel) "ancestral land or estate, patrimony." Meaning "collective assets of a dead person or debtor" is from 1830.

The three estates (in Sweden and Aragon, four) conceived as orders in the body politic date from late 14c. In France, they are the clergy, nobles, and townsmen; in England, originally the clergy, barons, and commons, later Lords Spiritual, Lords Temporal, and commons. For Fourth Estate see four.

old form of bowling, 1801, from four + corner (n.). So called because the four pins in it were set at the corners of a square.

of cars, 1957, from four + door.

"person who wears glasses," slang, 1874; see four + eye (n.).

"cheat, dishonest person," 1900, from verb four-flush "to bluff a poker hand, claim a flush (n.) while holding only four cards in the suit" (1896).

Old English feowerfeald; see four + -fold. As an adverb from 1530s. Similar formation in Old Frisian fiuwerfald, Dutch viervoudig, Old High German fiervalt, German vierfältig, Danish firfold, Gothic fidurfalþs.

c. 1300, fourefoted; see four + foot (n.). Replacing forms from Old English feowerfote.

bedstead with high corner posts, 1836, from four + post (n.).

"eighty, four times twenty," mid-13c., "formerly current as an ordinary numeral" [OED], from four + score (n.). Archaic by the time Lincoln used it at Gettysburg in 1863. Related: Fourscorth "eightieth."