a portion of time as limited and determined by some recurring phenomenon, as by the completion of a revolution of one of the heavenly bodies; a division of time, as a series of years, months, or days, in which something is completed, and ready to recommence and go on in the same order; as, the period of the sun, or the earth, or a comet.-a stated and recurring interval of time; more generally, an interval of time specified or left indefinite; a certain series of years, months, days, or the like; a time; a cycle; an age; an epoch; as, the period of the roman republic.-one of the great divisions of geological time; as, the tertiary period; the glacial period.  see the chart of geology.-the termination or completion of a revolution, cycle, series of events, single event, or act; hence, a limit; a bound; an end; a conclusion.-a complete sentence, from one full stop to another; esp., a well-proportioned, harmonious sentence.-the punctuation point [.] that marks the end of a complete sentence, or of an abbreviated word.-one of several similar sets of figures or terms usually marked by points or commas placed at regular intervals, as in numeration, in the extraction of roots, and in circulating decimals.-the time of the exacerbation and remission of a disease, or of the paroxysm and intermission.-a complete musical sentence.-to put an end to.-to come to a period; to conclude. [obs.] "you may period upon this, that," etc.