[gey-luh-sak; French gey-ly-sak] /ˌgeɪ ləˈsæk; French geɪ lüˈsæk/
noun
1.
Joseph Louis
[joh-zuh f loo-ee,, -suh f;; French zhaw-zef lwee] /ˈdʒoʊ zəf ˈlu i,, -səf;; French ʒɔˈzɛf lwi/ (Show IPA), 1778–1850, French chemist and physicist.
British Dictionary definitions for Gay-Lussac
Gay-Lussac
/ˈɡeɪˈluːsæk; French ɡɛlysak/
noun
1.
Joseph Louis (ʒozɛf lwi). 1778–1850, French physicist and chemist: discovered the law named after him (1808), investigated the effects of terrestrial magnetism, isolated boron and cyanogen, and discovered methods of manufacturing sulphuric and oxalic acids
Gay-Lussac in Science
Gay-Lussac
(gā'lə-sāk') French chemist and physicist who in 1808 developed a law governing the ratio of volumes of gases participating in chemical reactions. In that same year, with Louis Jacques Thénard, he discovered the element boron.