Definition of "illustration"

illustration

/ˌɪl.əˈstɹeɪ.ʃən/

noun
countable and uncountable, plural illustrations
1. The act of illustrating; the act of making clear and distinct;
2. The state of being illustrated, or of being made clear and distinct.
3. Something which illustrates; a comparison or example intended to make clear or apprehensible, or to remove obscurity.
  Quotations
  England will regard it as a measure of justice for Frank Lampard's disallowed goal against Germany in Bloemfontein at the 2010 World Cup - but it was also an illustration of how they rode their luck for long periods in front of a predictably partisan home crowd.
  2012 June 19, Phil McNulty, “England 1-0 Ukraine”, in BBC Sport‎
4. A picture designed to decorate a publication, or elucidate a literary work.
5. A calculated prevision of insurance premiums and returns (life insurance)