资料来源 : Webster's Revised Unabridged Dictionary (1913)

Cough \Cough\, v. t.
   1. To expel from the lungs or air passages by coughing; --
      followed by up; as, to cough up phlegm.

   2. To bring to a specified state by coughing; as, he coughed
      himself hoarse.

   {To cough down}, to silence or put down (an objectionable
      speaker) by simulated coughing.