"a violent, noisy effort to expel air from the lungs," early 14c., coughen, probably in Old English but not recorded, from Proto-Germanic *kokh-(source also of Middle Dutch kochen, Middle High German kuchen), with the rough "kh" of German or of Scottish loch. Onomatopoeic. Related: Coughed; coughing.
As a noun from c. 1300, "single act of coughing." As "illness or other condition that affects the sufferer with frequent coughs or fits of coughing," by 1742. Cough-drops attested by 1829; cough-medicine by 1828. To cough up "to present, hand over" is from 1894.
"whooping cough," 1670s (Sydenham), from Modern Latin pertussis, from per- "thoroughly," or here perhaps with intensive force (see per), + tussis "cough," a word of unknown origin.
1765, imitative of the sound of a cough; as an interjection of disgust, recorded from 1822. Form ough is from 1560s.
1540s, "to clear the throat, to cough up phlegm" (a sense now obsolete), from Old English hræcan "to cough up, spit" (related to hraca "phlegm"), from Proto-Germanic *khrækijan (source also of Old High German rahhison "to clear one's throat"), of imitative origin (compare Lithuanian kregėti "to grunt"). Meaning "make efforts to vomit" is from 1850; sense of "to vomit" is attested by 1888. Related: Retched; retching.