contagious

adjective4

1. •
   Easily transmitted to others.

   • Last year's flu strain was so contagious that everybody in town got sick!
2. •
   (figurative) Easily passed on to others.

   • Wearing jeans was a contagious fad at that time.
3. •
   Having a disease that can be transmitted to another person.

   • They were highly contagious, spreading bacteria to other people.
4. •
   Contiguous.