I'd like to suggest a clarification for the current entry, and the sentence "The act of exemplifying; a showing or illustrating by example".
While "The act of exemplifying" is indeed "a showing or illustrating by example", the act is not necessary for exemplification. In fact, the act is ostension, whereas exemplification may require more: possession of a property plus reference to its label.
Regards, J. Kopare
Reference: Goodman, Nelson, 1976, Languages of Art: An Approach to a Theory of Symbols. Indianapolis: Hackett Publishing Company, pp 52-57.