kənˈtājəs adjective
Etymology: Middle English, from Middle French contagieus, from Late Latin contagiosus, from Latin contagio + -osus -ous
1.
a. : communicable by contact : catching
contagious diseases
— compare infectious
b. : bearing contagion
many persons … are contagious long before they are aware of the presence of their disease — Journal American Medical Association
c. : for contagious diseases
a contagious ward
2. obsolete : causing disease : noxious
3. : spreading or communicable from one to another : exciting similar emotions or conduct in others
a contagious grin
contagious enthusiasm
: exciting enthusiasm : exciting response
contagious music
• con·ta·gious·ly adverb