infectious

/ɪnˈfɛkʃəs/
adjective
  1. Able to be passed from one person or animal to another; catching.
    • The flu is highly infectious and spreads quickly in schools.
    • The doctor warned that the disease is infectious even before symptoms appear.
    • Stay home if you have an infectious illness like chickenpox.
  2. Spreading quickly and easily to others (used about feelings, laughter, or enthusiasm).
    • Her laughter was infectious, and soon everyone in the room was giggling.
    • The team's infectious energy motivated the whole crowd.
    • His optimism is infectious; you can't help feeling positive around him.
What does "infectious" mean? | whatsthatwordmean | whatsthatwordmean