<p><strong>Adjective</strong></p><ul><li>Free from doubt as to the reliability, character, action, etc., of something.</li><li>Confident, as of something expected.</li><li>Convinced, fully persuaded, or positive.</li><li>Assured or certain beyond question.</li><li>Worthy of confidence; reliable; stable.</li><li>Unfailing; never disappointing expectations.</li><li>Unerring; never missing, slipping, etc.</li><li>Admitting of no doubt or question.</li><li>Destined; bound inevitably; certain.</li><li>Obsolete: secure; safe.</li><li>Be sure, to take care (to be or do as specified); be certain.</li></ul><p><strong>Adverb</strong></p><ul><li>Informal: certainly; surely.</li></ul>