A period of sexual inactivity in female mammals when they are not fertile or ready to reproduce.
From Greek 'an-' (without) + 'oestrus' (heat/sexual desire). The term emerged in veterinary and biological sciences in the 19th century to describe dormant reproductive cycles in animals.
Many animals don't stay fertile year-round—bears, deer, and dogs experience anoestrus to conserve energy. This biological rhythm helped ancient farmers predict breeding seasons and plan their livestock management before modern science explained the hormones behind it.
Complete word intelligence in one call. Free tier — 50 lookups/day.