contagious

The word “contagious” means capable of being passed from one person to another through contact. In plain terms, easily spread to others, whether it's an illness or an attitude.

“Contagious” is pronounced kuhn-TAYD-zhuhs (/kənˈteɪdʒəs/ in IPA).

Here is “contagious” used in a sentence: “The flu is highly contagious during the first few days of symptoms.”

Words with a similar meaning to “contagious” include catching.

The opposite of “contagious” — its antonyms — are non-contagious, noncontagious, noninfectious and nontransmissible.

“Contagious” is an adjective.

The word “contagious” comes from Late Latin. From Old French contagieus, from Late Latin contagiosus, from contagio ("contagion").

“Contagious” is an uncommon word in modern English.

"Contagious" specifically describes something capable of being passed from one person to another through contact, while "infectious" is a broader medical term that can include spread through air, water, or other means, not just direct contact. In everyday speech the two are often used interchangeably despite this technical distinction.

Yes, "contagious" also describes moods or behaviors that quickly spread to others, such as "contagious laughter" or "contagious enthusiasm." This figurative use captures how emotions can pass from person to person much like an illness.

"Contagious" is used comfortably in both settings, appearing in medical warnings about disease transmission as well as in casual descriptions of spreading moods or energy. Its meaning shifts slightly depending on whether it is applied literally to illness or figuratively to behavior.