fid
/fɪd/noun
1- chiefly Brit. or Nautical a thick peg, wedge, or supporting pin, in particular〈主英〉【航海】（粗钉、楔子或销子等）支撑材, 尤指：
1.1
- a square wooden or iron bar which takes the weight of a topmast stepped to a lower mast by being passed through holes in both masts桅栓。
1.2
- a conical pin or spike used in splicing rope（结绳用的）木笔。
词源
early 17th cent.: of unknown origin.