1. A well planned out and well executed personal prank.
2. A social experiment in which a group of people make reservations for popular restaurants and then bring large, stuffed fish beside which to sit during the meal, to the chagrin of other patrons.
3. A often costumed and seemingly random act of mischievious vandalism, usually accompanied by the words and phrases "Jonas", "Joner", "Jonas is Amish", "Penis", and especially "Nutsack".
As a verb:
To excute one of the aforementioned acts in a premeditated fashion.
"to ruckus" is often substituted for "to cause a ruckus"
The deviant youths planned a brilliant ruckus, involving painting a suspected communist classmate's driveway a brilliant crimson.
Unsuspecting, the schoolteacher was ruckused by masked teenagers wielding cucumbers and water balloon launchers.