<p><strong>Noun</strong></p><ul><li>foam or froth made by a detergent, especially soap, when stirred or rubbed in water, as by a brush used in shaving or by hands in washing.</li><li>foam or froth formed in profuse sweating, as on a horse.</li><li>Informal. a state of excitement, agitation, nervous tension, or the like: He was in a lather over my delay.</li></ul><p><strong>Verb</strong></p><ul><li>to form a lather: a soap that lathers well.</li><li>to become covered with lather, as a horse.</li><li>to apply lather to; cover with lather: He lathered his face before shaving.</li><li>Informal. to beat or whip.</li></ul>