<p><strong>Noun</strong></p><ul><li>Also called stack</li><li>A pipe for the escape of the smoke or gases of combustion, as on a steamboat, locomotive, or building</li></ul><p><strong>Adjective</strong></p><ul><li>Pertaining to, engaged in, or dependent on a basic heavy industry, as steel or automaking: smokestack companies</li></ul>