Definition

Noun 1. A period of sexual dormancy or inactivity in female mammals: This term specifically refers to the phase in the reproductive cycle when the female is not in heat (estrus). It is the time between two periods of sexual receptivity and ovulation.

Usage

• This is a technical, biological term used primarily in veterinary science, zoology, and animal husbandry.
• It applies to nonhuman mammals. The equivalent state in humans is not typically called "anestrus."
• It describes a natural, cyclical state, not necessarily a pathological condition.

Examples

• The researchers monitored the sheep to determine the length of anestrus between breeding seasons.
• After giving birth, the female dog entered a prolonged period of anestrus.
• The study compared hormonal levels during estrus and anestrus.

Advanced Usage

• Seasonal anestrus: A prolonged period of sexual inactivity triggered by environmental factors like day length, common in species like horses (long-day breeders) and sheep (short-day breeders).
• Lactational anestrus: The suppression of the estrous cycle caused by the hormonal effects of nursing offspring.
• Postpartum anestrus: The period of sexual inactivity following parturition (giving birth).

Variants and Related Words

• Anestrous (adjective): Of or relating to anestrus.
  • The animal was in an anestrous state.
• Estrus (noun): The period of sexual receptivity and fertility in female mammals; heat.
• Diestrus (noun): The period of sexual quiescence between estrus cycles, often considered a sub-phase within the broader cycle, sometimes used interchangeably with "anestrus" in a narrower sense.

Synonyms

• Sexual inactivity
• Dicestrus (in some classification systems)
• Quiescence (in a reproductive context)

Antonyms

• Estrus
• Heat
• Sexual receptivity

Noun

1. applies to nonhuman mammals: a state or interval of sexual inactivity between two periods of estrus