TLFi

Étymol. et Hist. 1843-48 (C. Lyell, Principes de géol., vol. 4, p. 443 ds Mack. t. 1, p. 217). Empr. à l'angl.devonian (du nom du comté de Devon en Angleterre), terme de géol. dep. 1837 (Sedgwick & Murchinson in Trans. geol. Soc., Ser. II, v. 707 ds NED : We propose therefore for the future to designate these groups [the Cornish Killas and the Devonian slates] collectively by the name Devonian system as involving no hypotheses and being agreeable to analogy).