Meaning of the word "courtesy is contagious" in English

What does "courtesy is contagious" mean in English? Explore the meaning, pronunciation, and specific usage of this word with Lingoland.

courtesy is contagious

US /ˈkɝː.t̬ə.si ɪz kənˈteɪ.dʒəs/
UK /ˈkɜː.tə.si ɪz kənˈteɪ.dʒəs/
"courtesy is contagious" picture

Phrase

a proverb meaning that when one person acts politely, others are likely to follow their example and be polite as well

Example:
The teacher reminded the students that courtesy is contagious, so they should be kind to one another.
Smile at your customers; remember, courtesy is contagious.