lacking clear expression, having imprecise meaning, or stated in indefinite legal terms; e.g., alimony statutes are inherently vague because they are applied on a discretionary basis with almost infinite variations.
is a linguistic sleight of hand. In contrast with ambiguity which has two or more different but usually quite precise meanings, vagueness lacks a precise meaning. This may occur when no agreement can be reached whether the word or its contradictory applies to a given situation, when the word has borderline applications, and when the denotation of the word is not precisely known or ascertainable from common usage and no way to delimit or determine its application. An argument contains a premise, or a conclusion, Q, the meaning of which is indeterminate. The indeterminateness of Q makes it impossible to assess Q's acceptability as a premise or its significance as a conclusion (Angeles, 1992, p. 328; Hughes, 1996, pp. 61-63, 243-244; Johnson & Blair, 1977, pp. 115-122).
Ambiguity is one way in which the meanings of words and phrases can be unclear, but there is another way, which is different from ambiguity: vagueness. For example, some men are definitely bald, and there is no debating the matter, for instance, Patrick Stewart (Captain Picard of Star Trek: The Next Generation). Other men are definitely not bald, for example, Bill Clinton.