I. lep-ˈtän noun
( plural lep·ta -ˈtä)
Etymology: New Greek, from Greek, a small coin, from neuter of leptos peeled, slender, small, from lepein to peel — more at leper
Date: circa 1741
: a former monetary unit equal to 1/100 drachma
II. ˈlep-ˌtän noun
Etymology: Greek leptos + English -on (II)
Date: circa 1929
: any of a family of particles (as electrons, muons, and neutrinos) that have spin quantum number 1/2 and that experience no strong forces
• lep·ton·ic lep-ˈtä-nik adjective