<p><strong>Noun</strong></p><ul><li>A space entirely devoid of matter.</li><li>An enclosed space from which matter, especially air, has been partially removed so that the matter or gas remaining in the space exerts less pressure than the atmosphere (plenum).</li><li>The state or degree of exhaustion in such an enclosed space.</li><li>A space not filled or occupied; emptiness; void: The loss left a vacuum in his heart.</li><li>A vacuum cleaner or sweeper.</li><li>Physics: A state of lowest energy in a quantum field theory.</li></ul><p><strong>Adjective</strong></p><ul><li>Of, pertaining to, employing, or producing a vacuum.</li><li>(Of a hollow container) partly exhausted of gas or air.</li><li>Pertaining to a device or process that makes use of a vacuum to accomplish a desired task.</li><li>Noting or pertaining to canning or packaging in which air is removed from the container to prevent deterioration of the contents.</li></ul><p><strong>Verb</strong></p><ul><li>(Used with object) To use a vacuum cleaner on; clean with a vacuum cleaner: to vacuum rugs.</li><li>To treat with any vacuum device, as a vacuum drier.</li><li>(Used without object) To use a vacuum cleaner: to vacuum in the dining room.</li></ul>