déduire

Forms

déduire^[1]

Etymology

It is borrowed from Latin dēdūcō (“to lead away, to subtract”), given a French shape after conduire and Old French duire.^[2][3][4][5] The Latin verb is formed of dē-, marking separation, and dūcō (“to lead”).^[3][6] Littré notes that the Latin verb had taken on the sense “divert, amuse”, much as divertir did.^[7]

Cognate with Old Occitan desduire.^[7]

Earliest recorded meaning

In the Vie de saint Alexis (about 1050) it means “to lead, bring”: the saint's father laments that his son has been led into great poverty in foreign lands.^[2][7]

Semantic evolution

In Old French it meant “lead, conduct”, with se déduire “go away”, and above all, figuratively, “divert, amuse”, as a pronominal from Chrétien de Troyes (1172) and as a transitive verb.^[3][4][2] The past participle became the noun déduit (about 1160) “pastime”, then “love-making”, archaic since the 17th century.^[3][4]

In the 14th century the verb took back from Latin the sense “subtract a sum” (1363), the usual one today.^[3][2] In the 16th century it meant “set out in detail” (before 1544, Marot) and acquired its logical sense, after déduction (before 1560, Du Bellay).^[2][3]

Timeline

• c. 1050 – “To lead” in the Vie de saint Alexis.^[2]
• c. 1160 – The noun déduit “pastime”.^[3]
• 1172 – Se déduire “enjoy oneself” in Chrétien de Troyes's Chevalier au lion.^[2][3]
• 1363 – “To subtract a sum”.^[2][3]
• before 1544 – Marot uses it for “set out in detail”.^[2]
• before 1560 – The logical sense, in Du Bellay.^[2]

Meanings

Verb

1. To deduct, subtract an amount from a total: déduire les frais de transport.^[8][2]
2. (dated) To set out in detail and in order.^[8][2][7]
3. (logic) To deduce, draw as a consequence from premises.^[8][7]
4. (reflexive) Se déduire: to follow as a consequence.^[7]

Word family

• déduit

Related words

• déductible
• déductif
• déduction
• conduire
• Latin dēdūcō

Usage notes

The noun déduit “pleasure, amorous pastime”, from the Old French sense “amuse”, is archaic.^[3][4]

References

1. ^ a b Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l 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 Rey, Alain, ed. (1992), Dictionnaire historique de la langue française, Paris: Le Robert
4. ^ a b c d Bloch, Oscar; Wartburg, Walther von (1989), Dictionnaire étymologique de la langue française, 8th ed., Paris: Presses universitaires de France
5. ^ Wartburg, Walther von, et al. (1922–2002), Französisches Etymologisches Wörterbuch, 25 vols., Bonn / Leipzig / Basel: Klopp / Teubner / Zbinden, p. 3, 171a
6. ^ Rey, Alain, ed. (2005), Le Grand Robert de la langue française, electronic version, Paris: Le Robert
7. ^ a b c d e f Littré, Émile (1873–1877), Dictionnaire de la langue française, 4 vols. and supplement, Paris: Hachette
8. ^ a b c Rey-Debove, Josette; Rey, Alain, eds. (2007), Le Petit Robert de la langue française, Paris: Le Robert