1 : able to be passed from one person or animal to another by touching
- a contagious disease
- It’s a highly contagious
2 : having a sickness that can be passed to someone else by touching
- I have a cold and I’m still contagious.
- I’m sick, but the doctor says I’m not contagious.
3 : capable of being easily spread to others : causing other people to feel or act a similar way
- She has a contagious
- contagious enthusiasm/laughter
— contagiously adverb