contagiousness
Contagiousness (noun) means the quality of being contagious, meaning easily passed from one person or thing to another. Example: “Scientists studied the contagiousness of the new virus strain.”
How to use contagiousness
Learner’s notesIn plain EnglishHow easily something spreads from person to person.
It sits in fairly formal or scientific writing more often than in casual speech.
Do not confuse it with contiguousness, which is about things touching or being next to each other, not spreading.
Trace the full origin ↓Fill the gap
Can you complete this real example?
Scientists studied the _____ of the new virus strain.
Etymology
The word is built from the adjective contagious with the suffix -ness added to turn it into a noun describing that quality.