n. [ L. illustratio: cf. F. illustration. ] 1. The act of illustrating; the act of making clear and distinct; education; also, the state of being illustrated, or of being made clear and distinct. [ 1913 Webster ]
2. That which illustrates; a comparison or example intended to make clear or apprehensible, or to remove obscurity. [ 1913 Webster ]
3. A picture designed to decorate a volume or elucidate a literary work. [ 1913 Webster ]