<p><strong>Noun</strong></p><ul><li>Pathology.<ul><li>A narrowing of the lumen of a blood vessel.</li><li>A congenital anomaly of the heart in which there is a narrowing of the aorta, resulting in abnormal blood flow.</li><li>Entomology: the condition of having the body enclosed in a hardened shell or puparium.</li></ul></li></ul>