<p><strong>Adjective</strong></p><ul><li>not definitely ascertainable or fixed, as in time of occurrence, number, dimensions, or quality</li><li>not confident, assured, or free from hesitancy</li><li>not clearly or precisely determined</li><li>indefinite</li><li>unknown</li><li>subject to change</li><li>variable</li><li>capricious</li><li>unstable</li><li>ambiguous</li><li>unreliable</li><li>undependable</li><li>dependent on chance or unpredictable factors</li><li>doubtful</li><li>of unforeseeable outcome or effect</li><li>unsteady or flickering, as light</li><li>of changing intensity or quality</li></ul><p><strong>Synonyms</strong></p><ul><li>unsure</li><li>unpredictable</li><li>irregular</li><li>undetermined</li><li>unsettled</li><li>vague</li><li>indistinct</li><li>not perfectly apprehended</li></ul>