rachet

n.  棘轮,棘齿; 救护车
v.  安装棘齿于……;把……造成棘齿形,于……作棘齿,在……上刻锯齿



英英释义

noun

  1. mechanical device consisting of a toothed wheel or rack engaged with a pawl that permits it to move in only one direction

      Synonym:    ratchetratch