géothermique

Forms

géothermique (plural géothermiques)^[1]

Etymology

The TLFi and the Grand Robert derive it from French géothermie + -ique;^[2][3] Wiktionary analyses it as from French géo- + thermique.^[1] The noun is itself first recorded later, by Littré in 1867, formed with géo- and -thermie, from the Greek root for “hot”.^[2][3]

Earliest recorded meaning

It is first recorded in 1860, in a text by Naudin quoted by Littré, meaning “relating to the heat of the earth”;^[2][4] Littré gives culture géothermique for growing plants with the help of the earth's heat.^[2][4]

Semantic evolution

It qualifies what concerns the internal heat of the earth and of its crust.^[5] In the 20th century it entered geophysics in degré géothermique and gradient géothermique, the depth corresponding to a rise of one degree in temperature, and energy policy in énergie géothermique.^[6][2][5] The GLLF also records it as a feminine noun, a synonym of géothermie (1962).^[6]

Timeline

• 1860 – Naudin uses it, as quoted by Littré.^[2][3]
• 1866 – Littré's dictionary records it.^[6]
• 1867 – Littré records the noun géothermie.^[2]
• 20th century – Degré, gradient and énergie géothermique appear.^[6]

Meanings

Adjective

1. geothermal: relating to the internal heat of the earth or to géothermie: une centrale géothermique.^[2][7]
2. Degré géothermique, gradient géothermique: the measure of the rise in the earth's temperature with depth.^[2][7]
3. Énergie géothermique: energy drawn from the earth's heat.^[2][6]

Related words

• géothermie
• thermique
• English geothermal

References

1. ^ a b c Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j 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 Rey, Alain, ed. (2005), Le Grand Robert de la langue française, electronic version, Paris: Le Robert
4. ^ a b Littré, Émile (1873–1877), Dictionnaire de la langue française, 4 vols. and supplement, Paris: Hachette
5. ^ a b Rey, Alain, ed. (1992), Dictionnaire historique de la langue française, Paris: Le Robert
6. ^ a b c d e Guilbert, Louis; Lagane, René; Niobey, Georges, eds. (1971–1978; 1989), Grand Larousse de la langue française, Paris: Larousse
7. ^ a b Rey-Debove, Josette; Rey, Alain, eds. (2007), Le Petit Robert de la langue française, Paris: Le Robert