antitussive \antitussive\ a. 1. having ability to to suppress or relieve coughing; -- of chemical substances. [WordNet 1.5 +PJC]
antitussive \antitussive\ n. 1. a medicament used to suppress or relieve coughing; an antitussive substance. Note: Codeine is one such commonly used antitussive. [WordNet 1.5 +PJC]