Best definition
The condition of temporary insanity resulting from obsessive perusal of Yahoo Groups message boards.
Amy’s lost her mind! All she wanted was access to various parenting techniques but got so tangled up in fear mongering on Yahoo Groups that she lost all perspective and found out there wasn’t a single thing she was doing that would label her as a good parent. It would take years of therapy to rediscover that she was indeed a good parent and had simply been yahooed.
yahooed: define #2
A VERB meaning deceived ,cheated, taken advantage of, lied to or mislead, as in “you just got skrewed”
A CEO that makes a public statement, that if the another company wants to make a deal, they better bring “Boatloads of Cash” to the table.

After luring investors , turns around and makes a deal for no “Boatloads of Cash”

“Y’all got yahooed now ” says the CEO as she disappears into hiding.
yahooed: define #3
An adjective describing a Yahoo group that has been deleted by their tightass censors.
“Aw, dammit, I spend hours setting up that group and then it got yahooed!”
yahooed: define #4
from a guest post in a yahoo story:

You know how you are reading a yahoo story? You see a headline that looks interesting, it talks about some amazing new find… discovery… 2 headed baby… but there is no picture. So much fail, from this day forward I will only refer to failure as yahooing.
“How did you do on that Latin test?” “Terrible, I think I yahooed it.”