One of the divisions of a year. The space of time denoted by this term varies according as one or another of the following varieties of months is intended:
Astronomical, containing one-twelfth of the time occupied by the sun in passing through the entire zodiac.
Calender, civil, or solar, which is one of the months in the Gregorian calendar, January, February, March, etc., which are of unequal length. Lunar, being the period of one revolution of the moon, or twenty-eight days.