periodes

Periodes is the plural of periode and is used in Dutch and other languages to describe several related ideas that share the notion of a span, segment, or boundary. In general use, a period denotes a length of time with a defined start and end, for example historical eras (the Middle Ages), geological periods (the Jurassic), or calendar intervals (the 20th century). Periods help organize events and developments into coherent sequences.

In biology and medicine, the term also refers to cyclic phenomena that repeat regularly. The most familiar is the menstrual period—a monthly cycle during which the body prepares for possible pregnancy and, in many people, shedding of the uterine lining occurs. The duration typically ranges from about 3 to 7 days and cycle length can vary.

In punctuation, a period is the dot at the end of a sentence. It marks the end of declarative statements, abbreviations, and, in many languages, also decimal points and thousands separators.

In music theory, a period is a pair of musical phrases that ends with a sense of closure, typically an imperfect or perfect cadence.

In science, the term is used in the periodic table to refer to a horizontal row of elements; the properties of elements change gradually across a period.

As a plural form, periodes may refer to multiple such spans or cycles, or simply to the Dutch plural of the word in multilingual contexts.