noun
mastectomy
Medical term for surgical removal of the breast, typically used in clinical contexts.
彼女は乳がんの治療のために乳房切除術を受けた。
She underwent a mastectomy for breast cancer treatment.
Compound of 乳房 (nyūbō, 'breast') + 切除 (setsujo, 'excision') + 術 (jutsu, 'surgery').