Infectious

/ɪnˈfɛkʃəs/

adjectivemedium🔥Very CommonMedical
2 meanings3 idioms/phrases3 questions

Definitions

2 meanings
1

Capable of being transmitted, especially a disease or illness.

/ɪnˈfɛkʃəs/

adjectiveneutralmedium
Medical

Capable of causing or spreading disease.

The virus is very infectious, so we need to be careful.

💡 Simply: Imagine your friend catches a cold, and soon everyone around them starts sneezing! That cold is infectious – it can spread easily from one person to another.

👶 For kids: If something is infectious, it means it can make other people sick, like a cold or the flu!

More Examples

2

The doctor isolated the patient because they had an infectious disease.

3

Handwashing is an important preventative measure against infectious illnesses.

How It's Used

Medical

"The doctor warned that the illness was highly infectious and could easily spread."

2

Spreading or capable of spreading rapidly to others; inspiring enthusiasm or excitement.

/ɪnˈfɛkʃəs/

adjectivepositivemedium
Medical

Causing or characterized by the spread of influence or enthusiasm.

Her positive attitude was infectious and brightened everyone's mood.

💡 Simply: Have you ever seen someone yawn and then you start yawning too? Or maybe you heard a great song and couldn't stop smiling? That's an example of something infectious, but it's not a sickness – it's a good feeling that spreads.

👶 For kids: Sometimes, the way someone laughs or is happy can make other people happy too! That's like infectious, but not like a yucky sickness!

More Examples

2

The team's enthusiasm for the project was infectious.

3

The comedian's infectious humor had the audience in stitches.

How It's Used

Figurative

"Her laughter was infectious; soon everyone in the room was giggling."

Tip:Think of something spreading like an infection, but it's positive, like laughter.

Synonyms & Antonyms

Idioms & expressions

Infectious disease

A disease caused by the invasion of the body by pathogenic microorganisms (such as bacteria, viruses, or parasites).

"The study focuses on the spread of infectious diseases within crowded urban areas."

Highly infectious

Describes something that spreads easily and quickly.

"The new strain of the virus is considered highly infectious, causing many cases."

An infectious smile/laugh

A smile or laugh that causes others to smile or laugh as well.

"Her infectious laugh always brightens my day."

From Latin *infectiōsus*, meaning 'tainted' or 'contaminated', from *inficere* ('to put into'), from *in-* ('in') + *facere* ('to make, do'). Originally used to describe diseases or conditions capable of being transmitted.

Originally, the word was used to describe diseases and processes of contamination, with connotations of 'tainting'. The figurative use, relating to spreading enthusiasm, is a later development.

Memory tip

Think of an infection that's spreading. It is infectious.

Word Origin

LanguageLatin
Original meaning

"to put into, to taint"

highly infectiousinfectious diseaseinfectious laughinfectious smile

Common misspellings

infeciousinfectuous

Usage

40%Spoken
60%Written