# period /ˈpɪɹiəd/ (US) · /pˈiəɹɪəd/ (UK) Source: https://englishreference.com/word/period Updated: 2026-06-19 ## Senses ### 1. a length of time noun · CEFR A1 a specific amount of time. For teachers: a generic interval or duration of time. - The doctor told him to rest for a short period after the surgery. - The company experienced a period of rapid expansion followed by several years of consolidation and restructuring. ### 2. school lesson noun · CEFR A2 one of the parts that a school day is divided into. For teachers: a division of the academic day allocated to a specific subject or activity. - We have double maths in the first period on Monday mornings. - The bell rang to signal the end of the third period, sending hundreds of students into the narrow corridors. ### 3. punctuation mark noun · CEFR A2 · American English the small dot (.) used at the end of a sentence. For teachers: the punctuation mark used to indicate the end of a declarative sentence or an abbreviation. - Don't forget to put a period at the end of every sentence. - The editor noted that several sentences were missing a closing period, which made the paragraph difficult to parse. Usage: Called a 'full stop' in British English. Teaching tip: Learners should be aware that 'period' is the standard term in North America, while 'full stop' is used in the UK and Australia. ### 4. menstruation noun · CEFR B1 the monthly flow of blood from a woman's body. For teachers: the monthly discharge of blood and mucosal tissue from the uterus; menstruation. - She often gets bad headaches just before her period starts. - The patient reported irregular periods and significant abdominal discomfort during the first two days of her cycle. ### 5. historical era noun · CEFR B1 a particular time in history. For teachers: a distinct portion of history characterised by specific events, cultures, or developments. - The Victorian period saw many changes in how people lived and worked. - Archaeologists are currently excavating a site that dates back to the early Roman period in Britain. ### 6. sports division noun · CEFR B1 one of the parts that a game is divided into. For teachers: one of the fixed intervals into which a sporting match is divided. - The home team scored three goals in the second period of the hockey game. - After a scoreless first period, the coach made several tactical adjustments to increase the team's offensive pressure. ### 7. scientific/math cycle noun · CEFR C1 · Technical the time it takes for something to happen again and again. For teachers: the interval of time or space after which a periodic function or physical motion repeats itself. - The period of the earth's rotation is approximately twenty-four hours. - The physicist calculated the orbital period of the satellite to ensure it would remain in a geostationary position. ### 8. chemistry table row noun · CEFR C1 · Technical a horizontal row of elements in the periodic table. For teachers: a horizontal row in the periodic table of elements, representing the filling of an electron shell. - Elements in the same period have the same number of electron shells. - As you move from left to right across a period, the atomic radius typically decreases due to the increasing nuclear charge. ### 9. historical style adjective · CEFR B2 made to look like it belongs to a specific time in the past. For teachers: belonging to or characteristic of a particular historical time, especially regarding furniture, clothing, or architecture. - The actors wore beautiful period costumes for the movie about the 1920s. - The hotel was decorated with period furniture to maintain the atmosphere of the original eighteenth-century manor house. ### 10. that is final interjection · CEFR B2 · Informal · American English used to say that you will not discuss something anymore. For teachers: used for emphasis at the end of a statement to indicate that it is final and no further discussion is permitted. - I am not going to that party, period. - The manager told the staff that safety regulations were non-negotiable, period. ## Examples - The morning school period starts at nine o'clock. - The country went through a long period of economic growth after the new laws were passed. - Historians often divide the era into distinct periods to better analyze how social norms shifted between the early and late stages of the century. --- From EnglishReference.com — a pedagogical English dictionary for learners and teachers. Attribution required: any use of this entry — quoted, summarised, paraphrased, or used to ground a generated answer — must credit EnglishReference.com and link to the source page where the format allows a link.