What does oestrous mean?
Oestrous is an adjective meaning relating to estrus, the recurring period during which a female mammal is sexually receptive and biologically capable of mating. It is commonly used in veterinary medicine, animal breeding, zoology, and biological research, especially when discussing an oestrous cycle, period, or pattern of behaviour. The term may describe a female animal that is in heat, but it normally has a more technical or scientific tone than such everyday wording. Oestrous is the standard British spelling; the American spelling is estrous. The word comes ultimately from Greek oistros, a term associated both with the gadfly and with frenzy or restless excitement. That history links the insect's persistent buzzing with the conspicuous activity and reproductive readiness associated with this biological state.
adjectiveOf or relating to estrus, the period of sexual receptivity in female mammals during which they are physiologically receptive to mating. The British spelling is oestrous; the US spelling is estrous.
- Relating to estrus or to the period of sexual receptivity in female mammals; in heat.
"The researcher monitored the cows' oestrous cycles to determine the best time for breeding."
"The veterinarian used ultrasound to track the dog's oestrous cycle."
"The study compared hormonal changes during the oestrous period in several species of farm animals."
Oestrous belongs to the language of reproduction: the word ultimately comes from Greek oistros, meaning both a gadfly and a fit of frenzy, linking the insect's restless buzzing with animals' sexual excitement.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does oestrous come from?
The word derives ultimately from Greek oistros, meaning a gadfly and, by extension, a fit of frenzy or excitement. English borrowed the related noun oestrus for the period of sexual excitement in female animals, and the adjective oestrous developed from that vocabulary. The hormone-related words oestrogen and oestrone belong to the same derivational family, while estrogen reflects the American spelling convention.
How oestrous is actually used
This is chiefly a zoological or veterinary term and is usually associated with female mammals rather than human sexuality. British English generally uses oestrous, while American English uses estrous.
Easily confused with oestrous
Estrous is the American spelling of the British adjective oestrous; the two words have the same meaning.