becketn. 索環、環扣學術名詞救生圈索環：造船工程、機械工程滑車：造船工程索環：造船工程滑車索環：機械工程把手索：海事滑車底環：海事英文釋義(nautical) a short line with an eye at one end and a knot at the other; used to secure loose items on a ship