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Allin

infectious

adjectiveattested in dialogue

  • United States//ɪnˈfɛk.ʃəs//

Caused by an agent that enters the host's body (such as a bacterium, virus, parasite, or prion); often, also, transmitted among hosts via any of various routes (for example, contact, droplet-borne, airborne, waterborne, foodborne, fomite-borne, or bloodborne).

adjective

  1. 1

    Caused by an agent that enters the host's body (such as a bacterium, virus, parasite, or prion); often, also, transmitted among hosts via any of various routes (for example, contact, droplet-borne, airborne, waterborne, foodborne, fomite-borne, or bloodborne).

    Cancer is usually not infectious.

    More infectious diseases like the flu are usually less potent.

  2. 2

    Able to infect others; capable of transmitting pathogens.

    Despite feeling better, the patient is still infectious.

    I doubt that [saliva] is very infectious ... I don't think this is a normal route of transmission.

  3. 3

    Spreading quickly from one person to another.

    infectious smile

    Her enthusiasm for work can be really infectious.

    When Maisie first met Danny, she remembers that he had an infectious laugh and a love for music.

  4. 4

    informalMemorable and invoking excitement or interest.

    Pop music is more infectious than elevator music.

Etymology

Borrowed from New Latin īnfectiōsus. By surface analysis, infect + -ious.

Forms

comparative
more infectious
superlative
most infectious
The neighbouring pagesAlphabetical order follows the rules of the language, not byte values: an accent decides only between two otherwise identical words, and Spanish files Ñ as a letter of its own.

Lexical content from Wiktionary, under CC BY-SA 4.0 · Source entry · Data version 2026-08-23

Rank among the words of the OpenSubtitles 2018 corpus — film and television subtitles, so spoken rather than written usage (CC BY-SA 3.0).