Pronunciation: (kôf, kof),[key] —v.i. 1. to expel air from the lungs suddenly with a harsh noise, often involuntarily.
2. (of an internal-combustion engine) to make a similar noise as a result of the failure of one or more cylinders to fire in sequence.
3. to make a similar sound, as a machine gun firing in spurts.
—v.t. 1. to expel by coughing (usually fol. by up or out): to cough up phlegm. 2. cough up,Slang. a. to relinquish, esp. reluctantly; contribute; give.
b. to blurt out; state, as by way of making a confession: After several hours of vigorous questioning by the police, he finally coughed up the information.
—n. 1. the act or sound of coughing.
2. an illness characterized by frequent coughing.
3. a sound similar to a cough, a machine gun, or an engine firing improperly.