Search Result for "safe period":
Wordnet 3.0

NOUN (1)

1. that time during a woman's menstrual cycle during which conception is least likely to occur (usually immediately before of after menstruation); 



WordNet (r) 3.0 (2006):

safe period
    n 1: that time during a woman's menstrual cycle during which
         conception is least likely to occur (usually immediately
         before of after menstruation)