The Collaborative International Dictionary
Chin cough
Chin cough \Chin" cough"\ [For chink cough; cf. As. cincung long laughter, Scot. kink a violent fit of coughing, akin to MHG. k[=i]chen to pant. Cf. Kinknaust, Cough.] Whooping cough.
Wiktionary
chin cough
n. (context archaic English) whooping cough