1 Vagueness in Sentences and Words.  2 The primary application of 'vague' is to sentences, not to words. 3  But the vagueness of a sentence does not imply that vagueness of every constituent word.4  One vague word is enough. Vagueness in Sentences and Words.  2 The primary application of 'vague' is to sentences, not to words. 3  But the vagueness of a sentence does not imply that vagueness of every constituent word.