D defs.my
Entry 2 senses Webster, 1913

Ne plus ultra

//nā' plŭs ŭl'trə// · Ne plus ul·tra · IPA
01 The uttermost point to which one can go or attain; hence, the summit of achievement; the highest point or degree; the acme.
  1. 1.
    The uttermost point to which one can go or attain; hence, the summit of achievement; the highest point or degree; the acme.
  2. 2.
    A prohibition against proceeding further; an insuperable obstacle or limiting condition.[Obs. or R.]