D defs.my
Entry 1 sense Webster, 1913

Know-all

· Know·-all · IPA
01 n. One who knows everything; hence, one who makes pretension to great knowledge; a wiseacre; a know-it-all; -- usually ironical.
  1. 1.
    One who knows everything; hence, one who makes pretension to great knowledge; a wiseacre; a know-it-all; -- usually ironical.[Colloq. or R.]