 Ambiguity and vagueness also contrast with respect to the speaker’s discretion. If a word is ambiguous, the speaker can resolve the ambiguity without departing from literal usage. For instance, he can declare that he meant ‘child’ to express the concept of an immature offspring. If a word is vague, the speaker cannot resolve the borderline case. For instance, the speaker cannot make ‘child’ literally mean anyone under eighteen just by intending it. That concept is not, as it were, on the menu corresponding to ‘child’. He would be understood as taking a special liberty with the term to suit a special purpose. Acknowledging departure from ordinary usage would relieve him of the obligation to defend the sharp cut-off.