Definition of freemartin in US English:



  • A hermaphrodite or imperfect sterile female calf which is the twin of a male calf whose hormones affected its development.

    • ‘Lillie looked at the anatomical characteristics of the freemartin, the sexually abnormal co-twin of a male calf, usually possessing female as well as male external genitalia.’
    • ‘Also the male co-twins to freemartins are usually considered to be normal and fertile, although a few may have underdeveloped testicles and some may have reduced fertility.’
    • ‘One heifer was later found as a freemartin and, therefore, was excluded from the trial.’
    • ‘The odds that she is a freemartin is really high.’
    • ‘Of the 42 animals studied, 10 freemartins were found with variable percentages of male and female blood cells, the majority however showing similar percentages of both.’
    • ‘Although the external genitalia of the freemartin may appear normal, the internal organs are abnormal in greater or lesser degrees.’
    • ‘These females are referred to as ‘freemartins’, don't ask me why.’
    • ‘If someone sold a 6-9 month old heifer at the sale barn I would assume they were intended as feeders, but how would they know (unless they knew they were twins to bulls) that they were freemartins at that young an age?’
    • ‘Consequently, freemartins are sterile and are usually slaughtered or sold for beef.’
    • ‘In cattle, there is a phenomenon called the freemartin.’
    • ‘Also, the ovaries of a freemartin do not produce the hormones necessary to induce the behavioral signs of heat.’
    • ‘The external appearance of a freemartin may vary from an apparently normal female to a somewhat masculinized individual.’
    • ‘Thus primates differ from cattle in which the freemartin animal is frequently infertile and virilized.’


Late 17th century: of unknown origin.