<p><strong>Adjective</strong></p><ul><li>of, situated, or for use under the arm or in the armpit: an underarm deodorant.</li><li>underhand: an underarm pitch in softball.</li></ul><p><strong>Noun</strong></p><ul><li>armpit.</li></ul><p><strong>Adverb</strong></p><ul><li>underhand.</li></ul>