adj · 7 senses · updated from the 2026-07-25 local source snapshot
Definitions and examples are grouped by meaning. Pronunciation, history, word forms, translations, descendants, synonyms, antonyms, derived terms, and related words appear whenever the source provides them.
Sound
Pronunciation
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CMU ARPABET:IH2 N F EH1 K SH AH0 S
Digits mark lexical stress: 1 primary, 2 secondary, 0 unstressed.
1
adj
Meaning 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).
Definition source: English Wiktionary via Wiktextract
Topics: medicine, pathology, sciences
Examples
Cancer is usually not infectious.
More infectious diseases like the flu are usually less potent.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
2
adj
Meaning 2
Able to infect others; capable of transmitting pathogens.
Definition source: English Wiktionary via Wiktextract
Qualifier: typically of a person
Topics: medicine, pathology, sciences
Examples
Despite feeling better, the patient is still infectious.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
3
adj
Meaning 3
Spreading quickly from one person to another.
Definition source: English Wiktionary via Wiktextract
Examples
infectious smile
Her enthusiasm for work can be really infectious.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
4
adj
Meaning 4
Memorable and invoking excitement or interest.
Definition source: English Wiktionary via Wiktextract
Usage: informal
Examples
Pop music is more infectious than elevator music.
Meaning relationships
Synonyms: none provided
Antonyms: none provided
5
adjective
Meaning 5
easily spread- Bertrand Russell
Definition source: Princeton WordNet 3.0
Examples
fear is exceedingly infectious; children catch it from their elders
Meaning relationships
Synonyms: none provided
Antonyms: noninfectious
6
adjective
Meaning 6
of or relating to infection
Definition source: Princeton WordNet 3.0
Examples
infectious hospital
infectious disease
Meaning relationships
Synonyms: none provided
Antonyms: none provided
7
adjective satellite
Meaning 7
caused by infection or capable of causing infection
Definition source: Princeton WordNet 3.0
Examples
viruses and other infective agents
a carrier remains infective without himself showing signs of the disease
Meaning relationships
Synonyms: infective
Antonyms: none provided
History
Etymology
Borrowed from New Latin īnfectiōsus. By surface analysis, infect + -ious.
Across languages
Translations
87 source translations are retained for this English entry.
Arabic:
مُعْدٍ
(muʕdin)
— transmitted between persons as illness
Azerbaijani:
sirayət edən
— transmitted between persons as illness
Azerbaijani:
yoluxucu
— transmitted between persons as illness
Azerbaijani:
sirayətedici
— transmitted between persons as illness
Bashkir:
йоғошло
(yoğoşlo)
— transmitted between persons as illness
Bengali:
সংক্রামক
(śoṅkramok)
— transmitted between persons as illness
Bengali:
ছোঁয়াচে
(chō̃ẇace)
— transmitted between persons as illness
Bulgarian:
заразен
(zarazen)
— transmitted between persons as illness
Catalan:
infecciós
— transmitted between persons as illness
Czech:
nakažlivý
— transmitted between persons as illness
Czech:
infekční
— transmitted between persons as illness
Esperanto:
infekta
— transmitted between persons as illness
Finnish:
tarttuva
— transmitted between persons as illness
Finnish:
tartuntavaarallinen
— transmitted between persons as illness
French:
infectieux
— transmitted between persons as illness
German:
infektiös
— transmitted between persons as illness
Hindi:
संक्रामक
(saṅkrāmak)
— transmitted between persons as illness
Indonesian:
infeksius
— transmitted between persons as illness
Indonesian:
menular
— transmitted between persons as illness
Ingrian:
tarttuva
— transmitted between persons as illness
Irish:
tógálach
— transmitted between persons as illness
Italian:
infettivo
— transmitted between persons as illness
Japanese:
感染性
— transmitted between persons as illness
Kazakh:
жұқпалы
(jūqpaly)
— transmitted between persons as illness
Kazakh:
инфекциялық
(infeksiälyq)
— transmitted between persons as illness
Malay:
berjangkit
— transmitted between persons as illness
Māori:
hōrapa
— transmitted between persons as illness
Māori:
hopuhopu
— transmitted between persons as illness
Norwegian Bokmål:
smittsom
— transmitted between persons as illness
Polish:
zaraźliwy
— transmitted between persons as illness
Polish:
zakaźny
— transmitted between persons as illness
Polish:
infekcyjny
— transmitted between persons as illness
Portuguese:
infeccioso
— transmitted between persons as illness
Romanian:
infecțios
— transmitted between persons as illness
Russian:
зара́зный
(zaráznyj)
— transmitted between persons as illness
Russian:
инфекцио́нный
(infekciónnyj)
— transmitted between persons as illness
Scottish Gaelic:
gabhaltach
— transmitted between persons as illness
Spanish:
infeccioso
— transmitted between persons as illness
Swedish:
infektiös
— transmitted between persons as illness
Tagalog:
nakahahawa
— transmitted between persons as illness
Welsh:
heintus
— transmitted between persons as illness
Arabic:
مُعْدٍ
(muʕdin)
— able to infect others
Bulgarian:
заразен
(zarazen)
— able to infect others
Bulgarian:
инфекциозен
(infekciozen)
— able to infect others
Catalan:
infecciós
— able to infect others
Czech:
nakažlivý
— able to infect others
Finnish:
tartuntavaarallinen
— able to infect others
French:
contagieux
— able to infect others
German:
infektiös
— able to infect others
Indonesian:
infeksius
— able to infect others
Indonesian:
menular
— able to infect others
Irish:
ionfhabhtaíoch
— able to infect others
Italian:
infettivo
— able to infect others
Italian:
contagioso
— able to infect others
Malay:
berjangkit
— able to infect others
Māori:
hōrapa
— able to infect others
Norwegian Bokmål:
smittsom
— able to infect others
Portuguese:
infeccioso
— able to infect others
Portuguese:
contagioso
— able to infect others
Romanian:
infecțios
— able to infect others
Russian:
зара́зный
(zaráznyj)
— able to infect others
Spanish:
infeccioso
— able to infect others
Spanish:
contagioso
— able to infect others
Swedish:
infektiös
— able to infect others
Tagalog:
nakahahawa
— able to infect others
Welsh:
heintus
— able to infect others
Arabic:
مُعْدٍ
(muʕdin)
— (of feelings and behaviour) spreading quickly between persons
Bulgarian:
инфекциозен
(infekciozen)
— (of feelings and behaviour) spreading quickly between persons
Catalan:
infecciós
— (of feelings and behaviour) spreading quickly between persons
Dutch:
aanstekelijk
— (of feelings and behaviour) spreading quickly between persons
Finnish:
tarttuva
— (of feelings and behaviour) spreading quickly between persons
French:
communicatif
— (of feelings and behaviour) spreading quickly between persons
German:
ansteckend
— (of feelings and behaviour) spreading quickly between persons
Icelandic:
smitandi
— (of feelings and behaviour) spreading quickly between persons
Indonesian:
viral
— (of feelings and behaviour) spreading quickly between persons
Malay:
berjangkit
— (of feelings and behaviour) spreading quickly between persons
Māori:
hōrapa
— (of feelings and behaviour) spreading quickly between persons
Māori:
ngahau
— (of feelings and behaviour) spreading quickly between persons
Norwegian Bokmål:
smittsom
— (of feelings and behaviour) spreading quickly between persons
Polish:
zaraźliwy
— (of feelings and behaviour) spreading quickly between persons
Russian:
зарази́тельный
(zarazítelʹnyj)
— (of feelings and behaviour) spreading quickly between persons
Swedish:
smittande
— (of feelings and behaviour) spreading quickly between persons
Welsh:
heintus
— (of feelings and behaviour) spreading quickly between persons
Bulgarian:
заразителен
(zarazitelen)
— informal: memorable and invoking excitement or interest
Czech:
nakažlivý
— informal: memorable and invoking excitement or interest
Dutch:
aanstekelijk
— informal: memorable and invoking excitement or interest
Finnish:
tarttuva
— informal: memorable and invoking excitement or interest
