The story
- Cantonese · derived from沈
- Cantonese · borrowed from岑
- English todayShum
Borrowed from Cantonese 岑 (sam4) or Cantonese 沈 (sam2), when the initial was still [ɕ] during the late 19th and early 20th centuries.
Etymology from Wiktionary, CC BY-SA 4.0.