fissile

Forms

fissile (plural fissiles)^[1]

Etymology

It is borrowed from Latin fissilis (“that can be split, easy to split”),^[2][3][4][5] from fissus (“split”), the past participle of findō (“to split”),^[2] the verb that gave fendre.^[2][3]

Its use in nuclear physics, from about 1950, was taken from English, as was fission.^[3]

Earliest recorded meaning

It is first found in 1566 in Du Pinet's translation of Pliny, applied to an onion, in the sense of something that splits easily; the record stays isolated until the middle of the 18th century.^[2][3]

Semantic evolution

The word was taken up again in the 18th century in mineralogy, where Buffon uses it of minerals that tend to split into sheets;^[2][3] the Grand Robert and the GLLF date this revival from 1842, in Mozin's dictionary.^[4][5] Littré still gives it only as a term of natural history, for a rock that tends to split into layers.^[6]

In the middle of the 20th century it took the sense “able to undergo nuclear fission”, after English;^[3][5] matières fissiles is the term for the fissile materials such as plutonium 239 and enriched uranium.^[2][5] The derivative of fission, fissible, is used as a synonym in that sense.^[3][7]

Timeline

• 1566 – Du Pinet's Pliny uses it of an onion.^[2]
• Mid-18th century – Buffon takes it up in mineralogy.^[2][3]
• 1842 – Mozin's dictionary records it again, in the sense “tending to split into layers”.^[4][5]
• c. 1950 – The physics sense “able to undergo nuclear fission” is borrowed from English.^[3]

Meanings

Adjective

1. (mineralogy) Of a rock or mineral, tending to split into thin sheets or layers, as schiste: une ardoise très fissile.^[2][7][8]
2. (physics) Able to undergo nuclear fission; also said of a nucleus or atom: matières fissiles.^[2][5][9]

Related words

• fendre
• fission
• fissible
• Latin fissilis

References

1. ^ a b 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 d e f g h i Rey, Alain, ed. (1992), Dictionnaire historique de la langue française, Paris: Le Robert
4. ^ a b c Rey, Alain, ed. (2005), Le Grand Robert de la langue française, electronic version, Paris: Le Robert
5. ^ a b c d e f Guilbert, Louis; Lagane, René; Niobey, Georges, eds. (1971–1978; 1989), Grand Larousse de la langue française, Paris: Larousse
6. ^ Littré, Émile (1873–1877), Dictionnaire de la langue française, 4 vols. and supplement, Paris: Hachette
7. ^ a b Rey-Debove, Josette; Rey, Alain, eds. (2007), Le Petit Robert de la langue française, Paris: Le Robert
8. ^ Dictionnaire de français Larousse, larousse.fr/dictionnaires/francais (accessed 2024)
9. ^ Dictionnaire Le Robert en ligne, dictionnaire.lerobert.com (accessed 2024)