period
名词 period:
an amount of time
同义词:time period, period of time
one of three periods of play in hockey games
a stage in the history of a culture having a definable place in space and time
同义词:historic period, historical period
the interval taken to complete one cycle of a regularly repeating phenomenon
the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause--Aristotle
同义词:menstruation, menses, menstruum, catamenia, flow
a punctuation mark (.) placed at the end of a declarative sentence to indicate a full stop or after abbreviations
同义词:point, full stop, stop, full point
a unit of geological time during which a system of rocks formed
the end or completion of something