<p><strong>Noun</strong></p><ul><li>lac that has been purified and formed into thin sheets, used for making varnish shellac varnish by dissolving it in alcohol or a similar solvent.</li><li>formerly, a phonograph record made of a breakable material containing shellac, especially one to be played at 78 r.p.m.: In the antique shop I found a stack of old shellacs with recordings of great wartime classics.</li></ul><p><strong>Verb (used with object)</strong></p><ul><li>shel·lacked, shel·lack·ing: to coat or treat with shellac.</li><li>Slang: to defeat; trounce.</li><li>to thrash soundly.</li></ul>