skean dhu
noun /ˌskiːən ˈduː/,  /ˌskiːn ˈduː/
  /ˌskiːən ˈduː/,  /ˌskiːn ˈduː/
- a knife which is worn inside a sock with traditional Scottish clothing用苏格兰传统服装穿在袜子里的刀 词源early 19th cent.: from skean (from Irish and Scottish Gaelic sgian ‘knife’) + Scottish Gaelic dubh ‘black’.