English Reference
adjective

contagious

adj.
US /kənˈteɪdʒəs/ UK /kəntˈeɪdʒəs/ con·ta·gious

  1. 01 B2 Upper Intermediate Medicine

    describes a disease that you can catch by being near or touching an infected person.

    capable of being transmitted by infection or direct contact. Often used to describe the disease itself or the person carrying it.

    Simple

    The doctor said he is still contagious, so he should stay home from school.

    In context

    Public health officials warned that the new strain of the virus is highly contagious, requiring stricter quarantine measures for those exposed.

    Pitfall
    He is contagious of the flu. He is contagious with the flu.

    Use 'with' to specify the illness, or simply say 'he is contagious' to mean he can spread it.

    infectiouscommunicabletransmissible
    non contagiousharmless
  2. 02 B2 Upper Intermediate

    describes a feeling, like a laugh or a yawn, that quickly spreads to other people.

    tending to spread from person to person through social contact or imitation; used figuratively for emotions, moods, or behaviours.

    Simple

    Her laughter was contagious, and soon the whole room was giggling.

    In context

    The captain's sense of calm proved contagious, steadying the nerves of the younger players as they entered the final minutes of the match.

The state has seen 393 cases of the highly contagious virus this year, as infections across the US have hit the highest point in 35 years.

BBC News· 25 Aug 2026

The condition is contagious and zoonotic and can be difficult to detect.

Phys.org· 15 Aug 2026

From Old French contagieus, from Late Latin contagiosus, from contagio.

Etymology adapted from Wiktionary, available under CC BY-SA 4.0.

This entry
Origin la-lat contagiosus
Level B2 · Upper Intermediate
Frequency Frequent
Updated