<p><strong>Noun</strong></p><ul><li>plural alveoli</li><li>a little cavity, pit, or cell, as a cell of a honeycomb</li><li>an air cell of the lungs, formed by the terminal dilation of tiny air passageways</li><li>one of the terminal secretory units of a racemose gland</li><li>the socket within the jawbone in which the root or roots of a tooth are set</li></ul>