IPA: //ˈfriːˌmɑːrtɪn//
KK: /ˈfriːˌmɑːrtɪn/
A female calf that is usually sterile and born alongside a male calf, often due to a shared placenta during pregnancy.
The farmer explained that the freemartin would not be able to reproduce because of its condition.
Freemartin is derived from the combination of 'free' (from Old English 'freo', meaning not in bondage or liberated) and 'martin' (from Old French 'martin', referring to a male animal, particularly a male of the species). The term specifically refers to a female calf that is born twin to a male calf and is often sterile, hence the implication of being 'free' from the ability to reproduce.
Think of a 'free' calf that cannot reproduce because it is a twin to a male — this helps you remember that a freemartin is a female calf that is often sterile.
No commonly confused words.