Synonyms of infectious

infectious

adjective

in-ˈfek-shəs 

as in spreading

exciting a similar feeling or reaction in others

an infectious giggle that got the whole class laughing

Synonyms & Similar Words

• spreading
• catching
• contagious
• epidemic
• overwhelming
• tangible
• irresistible
• perceptible
• winning
• overpowering
• palpable
• inviting
• endearing
• fetching
• disarming
• winsome

Example Sentences

Recent Examples of infectious

On top of bringing her infectious energy to school events, the actress also worked on the school newspaper and served as prom queen. — Grace Gavilanes, PEOPLE, 14 July 2026

There’s no evidence the parasite has evolved to become more infectious, said Dianna Blau, the CDC’s acting parasitic diseases branch chief. — Mike Stobbe, Los Angeles Times, 12 July 2026

It’s spread through contact with bits of human waste that have sat in a warm environment for a week or two, allowing the parasite to mature and become infectious. — Nicholas Florko, The Atlantic, 11 July 2026

There's no evidence that the parasite has evolved to become more infectious, said Dianna Blau, the CDC's acting parasitic diseases branch chief. — ABC News, 8 July 2026