English to English

noun (n)

• the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause(noun.process)

  Example:
  The women were sickly and subject to excessive menstruation.
  

  Synonym:
  catamenia, flow, menses, menstruum, period
  

  source: wordnet30
• The discharge of the menses; also, the state or the period of menstruating.(noun)

  source: webster1913