[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