e·ri·od (pîr-d)
n.
1. An interval of time characterized by the occurrence of a certain condition, event, or phenomenon: a period of economic prosperity.
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http://www.thefreedictionary.com/periodtime (tm)
n.
1.
a. A nonspatial continuum in which events occur in apparently irreversible succession from the past through the present to the future.
b. An interval separating two points on this continuum; a duration: a long time since the last war; passed the time reading.
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2.
a. An interval, especially a span of years, marked by similar events, conditions, or phenomena; an era. Often used in the plural: hard times; a time of troubles.
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4.
a. Periods or a period designated for a given activity: harvest time; time for bed.
http://www.thefreedictionary.com/time4. a limited period or interval, as between two successive events: a long time.
http://dictionary.reference.com/browse/time?s=t5. the point of completion of a round of time or of the time during which something lasts or happens.
http://dictionary.reference.com/browse/periodThat's why 'time' will not fit the sense of 'period'. Same in German. 'Zeit' differs from 'Zeitdauer', what signifies 'Dauer' or 'Periode'.