<p><strong>Noun</strong></p><ul><li>Anatomy: either of two muscles on each side of the upper and anterior part of the thorax.</li><li>The action of the larger pectoralis major assists in drawing the shoulder forward and rotating the arm inward.</li><li>The action of the smaller pectoralis minor assists in drawing the shoulder downward and forward.</li></ul><p><strong>End of Response</strong></p>