<p><strong>Noun</strong></p><ul><li>the nail of the thumb</li><li>anything quite small or brief, as a small drawing or short essay</li><li>Printing: a small, rough dummy</li><li>Also called porkchop</li><li>Journalism, Printing: a half-column portrait in a newspaper</li></ul><p><strong>Adjective</strong></p><ul><li>quite small or brief; concise: a thumbnail description of Corsica</li></ul><p><strong>Verb (used with object)</strong></p><ul><li>to make a thumbnail sketch or description of</li></ul>