Something that will happen when any or all of the following occur:

- Human sacrifice
- Dogs and cats living together
Peter Venkman: "Human sacrifice! Dogs and cats living together! Mass hysteria!"
by just passin thu August 7, 2010
A dude who says shit like they are reading to the friggin' Queen. A guy (or chick) who talks really proper and acts way too old for their age.

Derived from a student (david) in our modern world history class at Guilford Young College after he asked the teacher "why was there not mass hysteria?" instead of something more his age like "why didnt they go crazy?" or "why didn't they freak out?"

Usually teachers pet and gets special tutouring after school at teachers house.

Can be seen dancing in hallways at school.
Student one: "Whoa man! Check out the rack on that chick! Titty-fuck that bitch!"

Student two: "Indeed, I'd apreciate sitmulating my genitals upon her bosom"

Student one: "WTF? Your talking like Mass Hysteria now, act your age nigga!"
by Jack and Jasmin September 5, 2007
When fake or sensational videos are uploaded to YouTube and propelled by alarmist users into the mind of the general population, spawning urban myths, group-think, or panic.
"Dude did you hear that there is a hidden camera in your cable box watching you jerkoff?"

No way that's totally "YouTube Mass Hysteria "

by pizzatime February 25, 2009