Tonocard vs antiarrhythmic drug

Tonocard and antiarrhythmic drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
Tonocard	Yes	No	No	No
antiarrhythmic drug	Yes	No	No	No

As nouns, antiarrhythmic drug is a hypernym of Tonocard; that is, antiarrhythmic drug is a word with a broader meaning than Tonocard:

Tonocard: antiarrhythmic drug (trade name Tonocard) used to treat ventricular arrhythmias when less dangerous drugs have failed
antiarrhythmic drug: a drug used to treat an abnormal heart rhythm

Other hypernyms of Tonocard include antiarrhythmic, antiarrhythmic medication.

Tonocard (noun)	antiarrhythmic drug (noun)
antiarrhythmic drug (trade name Tonocard) used to treat ventricular arrhythmias when less dangerous drugs have failed	a drug used to treat an abnormal heart rhythm