[count] 1 : a length of time during which a series of events or an action takes place or is completed ▪ We have had two power failures in a five-month period. ▪ The period between Christmas and New Year's Eve is a very busy one for us. —often + of ▪ Two snowstorms hit the area in a period of one week. ▪ There was a brief period of silence. ▪ The country is in a period of economic growth. ▪ Scattered showers are expected with a few periods of sunshine. ▪ We didn't speak for a long period of time. —see also cooling-off period
2 : a length of time that is very important in the history of the world, a nation, etc. ▪ We are studying our country's colonial period.
3 : a time that is very important in the life of a person ▪ Picasso's Blue Period ▪ Children go through many changes during the period of adolescence.
4 a : one of the parts that a school day is divided into ▪ I have algebra class during third period. b : one of the parts that the playing time of a game (such as hockey) is divided into ▪ He scored a goal in the first period. ▪ The score was tied after two periods.
5 US a : a point . used to show the end of a sentence or an abbreviation —called also (Brit) full stop b —used in speech to emphasize that a decision, command, or opinion has been made and will not be changed ▪ You are not leaving this house, period. ▪ I don't want to talk to her again, period.
6 : menstrual period