Meaning of “contagious” - Learner’s Dictionary

contagious

adjective uk us /kənˈteɪdʒəs/
DISEASE

A contagious disease is one that you can get if you touch someone who has it.

FEELING

A contagious feeling spreads quickly amongst people:

Her excitement was contagious.

(Definition of “contagious” from the Cambridge Learner’s Dictionary © Cambridge University Press)