<p><strong>Verb</strong></p><ul><li>(used without object)<ul><li>re­lapsed, re­laps·ing.</li><li>to fall or slip back into a former state, practice, etc.: to relapse into silence.</li><li>to fall back into illness after convalescence or apparent recovery.</li><li>to fall back into vice, wrongdoing, or error; backslide: to relapse into heresy.</li></ul></li></ul><p><strong>Synonyms</strong></p><ul><li>lapse</li><li>revert</li><li>regress</li></ul><p><strong>Noun</strong></p><ul><li>an act or instance of relapsing.</li><li>a return of a disease or illness after partial recovery from it.</li></ul>