infectious

Definition

If something is infectious, it can be spread from one person or animal to another, especially diseases. It can also describe something that spreads easily, like laughter or enthusiasm.

Usage & Nuances

Often used for diseases but also for positive feelings like 'infectious laughter'. 'Infectious' is neutral or positive when used figuratively, and negative when talking about illness. Not to be confused with 'contagious', which is nearly a synonym but rarely used for emotions.

Example Sentences