donor; blood donor; organ donor
Most often used in medical contexts for a person who provides blood, an organ, bone marrow, or other biological material for treatment or transplant.
兄が骨髄移植のドナーになった。
My older brother became the donor for the bone marrow transplant.
He registered with the bone marrow bank and became a donor.
病院は適合するドナーを探している。
The hospital is looking for a compatible donor.
患者の家族は必死にドナーを探していた。
The patient's family was desperately searching for a donor.
A matching donor was finally found.
The everyday counter for people: 一人 (ひとり), 二人 (ふたり), 三人 (さんにん).
Used when counting the number of donors, especially in somewhat formal contexts.
donor card
Written in katakana as a modern medical/social term. No language of origin is specified, so the exact borrowing history is not stated here.