infectious

The word “infectious” means able to be passed from one person or animal to another, usually through germs. In plain terms, easily spread from one person to another — either a germ, or a mood like enthusiasm or laughter.

“Infectious” is pronounced ihn-FEHK-shuhs (/ɪnˈfɛk.ʃəs/ in IPA).

Here is “infectious” used in a sentence: “Chickenpox is highly infectious among young children.”

The opposite of “infectious” — its antonyms — are non-infectious and noninfectious.

“Infectious” is an adjective.

The word “infectious” comes from New Latin. From New Latin īnfectiōsus, from infect + -ious.

“Infectious” is a fairly common word in modern English, usually learned at around the B2 level.

“Infectious” has 2 distinct senses listed in this dictionary. The most common is: able to be passed from one person or animal to another, usually through germs.

Infectious describes something able to be passed from one person or animal to another, usually through germs, and is often used for diseases spread by any means, including air, water, or vectors. Contagious more narrowly implies spread through direct contact, though the two words are frequently used interchangeably in everyday speech.

Yes, infectious can describe moods or behaviours that quickly spread to affect other people, such as 'infectious enthusiasm' or 'infectious laughter,' where the sense is figurative rather than medical.

Infectious describes the capacity to spread germs to others, while infected describes a person or organism that already has germs within them. Someone can be infected without necessarily being infectious to others, and vice versa depending on the stage of illness.