the.com/infectious
Spreadable, whether it's a virus, a laugh, or a truly bad idea.
means Capable of being passed from one host to another, or used figuratively for moods and behaviors that spread just as easily.
from From Latin inficere, to dip into, taint, or spoil — the same root that gives us infect, picturing contamination as a literal dunking in something foul.
Vs contagiousInfectious spreads by germ; contagious by direct contact.
Mood versionLaughter and yawns count as socially infectious.
Medical spanIncludes bacteria, viruses, fungi, and parasites alike.