<p><strong>Noun</strong></p><ul><li>calendar month</li><li>any of the twelve parts, as January or February, into which the calendar year is divided</li><li>the time from any day of one calendar month to the corresponding day of the next</li><li>a period of four weeks or 30 days</li><li>solar month</li><li>one-twelfth of a solar or tropical year</li><li>lunar month</li><li>the period of a complete revolution of the moon around the earth</li><li>the period between successive new moons (synodic month), equal to 29.531 days</li><li>the period between successive conjunctions with a star (sidereal month), equal to 27.322 days</li><li>the period between successive perigees (anomalistic month), equal to 27.555 days</li><li>the period between successive similar nodes (nodical month, or draconic month), equal to 27.212 days</li><li>an unusually long period of time of indefinite length</li></ul>