Top definition
The Caucasian holiday where people eat lesser portions of food. It was first created when the Lord came down and gave Jesus food but it was too much. Jesus therefore rejected the parcel and the Lord lessened the amount in there and sent it back. Jesus then ate the smaller portion and was pleased and set up a remembrance of the event.
A: Dude, lets go get some massive amounts of food!

B: I can't dude, its yimmidum.

A: Thats rite i forgot nevermind.
by Bojangles20000 November 26, 2006
Happy St. Patties Day!