The meaning of PERIOD is the completion of a cycle, a series of events, or a single action : conclusion. How to use period in a sentence. Synonym Discussion of Period . Learn the various meanings and uses of the word period in English, from a length of time to a punctuation mark. Find synonyms, examples, pronunciation, and grammar tips for period . Definition Period and time period are two terms that are often used interchangeably, but they actually have slightly different meanings. A period is a length or portion of time, while a time period refers to a specific span of time. In other words, a period can be any duration of time, while a time period is a defined segment of time. Duration One key difference between period and time period is the duration they refer to. A period can be short or long, depending on the context in which it ... Period definition : a rather large interval of time that is meaningful in the life of a person, in history, etc., because of its particular characteristics.. See examples of PERIOD used in a sentence.