<p><strong>Noun:</strong></p><ul><li>A bag made of thin rubber or other light material, usually brightly colored, inflated with air or with some lighter-than-air gas and used as a children's plaything or as a decoration.</li><li>A bag made of a light material, as silk or plastic, filled with heated air or a gas lighter than air, designed to rise and float in the atmosphere and often having a car or gondola attached below for carrying passengers or scientific instruments.</li><li>(In drawings, cartoons, etc.) A balloon-shaped outline enclosing words represented as issuing from the mouth of the speaker.</li><li>An ornamental ball at the top of a pillar, pier, or the like.</li><li>A large, globular wineglass.</li><li>Chemistry Now Rare. A round-bottomed flask.</li></ul><p><strong>Verb (used without object):</strong></p><ul><li>To go up or ride in a balloon.</li><li>To swell or puff out like a balloon.</li><li>To multiply or increase at a rapid rate: Membership has ballooned beyond all expectations.</li></ul><p><strong>Verb (used with object):</strong></p><ul><li>To fill with air; inflate or distend (something) like a balloon.</li></ul><p><strong>Adjective:</strong></p><ul><li>Puffed out like a balloon: balloon sleeves.</li><li>Finance. (Of a loan, mortgage, or the like) having a payment at the end of the term that is much bigger than previous ones.</li></ul>