équerre

Forms

équerre f (plural équerres)^[1] Old French esquire (1170), esquierre (about 1275), also esquiere and esquerre; the spelling équerre dates from the 17th century.^[2][3][4]

Etymology

It is inherited from Old French esquire, inherited from Vulgar Latin *exquadra, a deverbal noun from Vulgar Latin *exquadrō (“to make square”), the verb behind équarrir.^[2][4][5][6] Wiktionary traces it further to quadrus (“square”).^[1] Bloch and Wartburg explain the name by the tool's use for drawing the corners of square things; the classical Latin word for it was norma.^[5]

Cognate with Italian squadra, Spanish escuadra and Occitan escaire.^[5][7] Wiktionary names escadre and the English square as doublets.^[1]

Earliest recorded meaning

In the Livre des Rois (1170) stones are cut à esquire, “square”: the first sense was a square shape or right angle.^[2][7][4]

Semantic evolution

From about 1275, in Jean de Meun's Roman de la Rose, the word names the instrument for drawing and checking right angles, the sense that has stayed in common use.^[2][4] It gave phrases for the angle itself: à l'esquierre “at a right angle” (about 1393), d'équerre (1740) and en équerre (1835).^[4][3] Fausse équerre, a bevel with movable arms for measuring any angle, is recorded in 1640.^[4][3]

By likeness of shape, it came to mean (1690) a T- or L-shaped iron piece used to strengthen joints in carpentry, then other instruments, such as the surveyor's équerre d'arpenteur (1870).^[4][2]

Timeline

• 1170 – A esquire “square” in the Livre des Rois.^[2]
• c. 1275 – Esquierre names the instrument in the Roman de la Rose.^[2]
• c. 1393 – A esquierre “at a right angle” in the Ménagier de Paris.^[2]
• 1640 – Oudin records fausse équerre.^[3]
• 1690 – Furetière records the sense “iron angle brace”.^[2][3]
• 1740 – The Académie records d'équerre.^[3]
• 1835 – The Académie records en équerre.^[3]
• 1870 – Larousse records équerre d'arpenteur.^[3]

Meanings

Noun

1. A square or set square: an instrument of wood, metal or plastic for drawing right angles and perpendiculars.^[2][8][1]
2. Double équerre: a T-square.^[8][3]
3. Fausse équerre: a bevel with movable arms, for drawing any angle.^[8][4]
4. Équerre d'arpenteur: a surveyor's cross, a hollow prism with slits for setting out perpendiculars on the ground.^[8]
5. An L- or T-shaped iron piece used to strengthen joints in carpentry or joinery; an angle bracket.^[2][4]
6. D'équerre, à l'équerre, en équerre: at a right angle.^[4][3]

Word family

• équerrer
• équerrage

Related words

• carrer
• équarrir
• escadre
• Latin quadrus

References

1. ^ a b c d e Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k Trésor de la langue française informatisé (2004), ATILF – CNRS & Université de Lorraine, atilf.fr/tlfi; electronic version of Imbs, Paul; Quemada, Bernard, eds. (1971–1994), Trésor de la langue française, Paris: CNRS / Gallimard
3. ^ a b c d e f g h i j Guilbert, Louis; Lagane, René; Niobey, Georges, eds. (1971–1978; 1989), Grand Larousse de la langue française, Paris: Larousse
4. ^ a b c d e f g h i j Rey, Alain, ed. (1992), Dictionnaire historique de la langue française, Paris: Le Robert
5. ^ a b c Bloch, Oscar; Wartburg, Walther von (1989), Dictionnaire étymologique de la langue française, 8th ed., Paris: Presses universitaires de France
6. ^ Rey, Alain, ed. (2005), Le Grand Robert de la langue française, electronic version, Paris: Le Robert
7. ^ a b Littré, Émile (1873–1877), Dictionnaire de la langue française, 4 vols. and supplement, Paris: Hachette
8. ^ a b c d Rey-Debove, Josette; Rey, Alain, eds. (2007), Le Petit Robert de la langue française, Paris: Le Robert