Meniscus

Chamber's Twientieth Century Dictionary · 1908 · p. 64

mē-nis′kus, n. a crescent or a new moon: a lens hollow on one side and bulging on the other.— adjs. Menis′cal ; Menis′cate ; Menis′ciform ; Menis′coid . [Gr. mēnē , the moon, -iskos , small.]