infectious
adjUS, UK /ɪnˈfɛk.ʃəs/
Etymology Borrowed from New Latin īnfectiōsus. By surface analysis, infect + -ious.
1
Medicine, Pathology, Sciences Of an illness 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.
Typically of a person
- 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.1981 December 1, Sue Hyde, quoting Paul Black, “AIDS Update: Little To Cheer About”, in Gay Community News, volume 12, number 20, page 3:
3
Of feelings and behaviour Spreading quickly from one person to another.
- infectious smile
- Her enthusiasm for work can be really infectious.
1 more example
- When Maisie first met Danny, she remembers that he had an infectious laugh and a love for music.2024 November 20, Fortesa Latifi, “How These Men Left the Manosphere — and Why Some May Never”, in Teen Vogue:
4
Informal Memorable and invoking excitement or interest.
- Pop music is more infectious than elevator music.
- Antonyms
- non-infectious, noninfectious
- Derived terms
- agroinfectious, antiinfectious, bovine infectious petechial fever, feline infectious peritonitis, hyperinfectious, infection, infectious abortion, infectious agent, infectious bovine rhinotracheitis, infectious disease, infectious disease specialist, infectiously, infectious mononucleosis, infectiousness, neuroinfectious, parainfectious, postinfectious, preinfectious, pseudoinfectious, reinfectious, subinfectious, superinfectious, toxicoinfectious, uninfectious