Functions

Because mathematicians get along with common words, many amusing ambiguities arise. For instance, the word function probably expresses the most important idea in the whole history of mathematics. Yet, most people hearing t would think of a 'function' as meaning an evening social affair, while others, less socially minded, would think of their livers.
By E. Kasner and J. Newman, quoted in More Random Walks in Science, an anthology compiled by Robert L Weber.