<p><strong>Adverb</strong></p><ul><li>At one time in the past; formerly.</li><li>A single time.</li><li>Even a single time; at any time; ever.</li><li>By a single step, degree, or grade.</li></ul><p><strong>Adjective</strong></p><ul><li>Former; having at one time been.</li></ul><p><strong>Conjunction</strong></p><ul><li>If or when at any time; if ever; whenever; as soon as.</li></ul><p><strong>Noun</strong></p><ul><li>A single occasion; one time only.</li></ul>