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.
He registered with the bone marrow bank and became a donor.
My older brother became the donor for the bone marrow transplant.
The hospital is looking for a compatible donor.
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.