Decked out with an exorbitant array of Christmas or holiday lights. Usually in reference to a house but can apply to other properties. The name is in reference to the lead character in the movie Christmas Vacation, Clark W.Griswald, JR. who decorates the outside of the house with 250 strands of lights with 100 bulbs on each strand for a total of 25,000 light bulbs, enough to make the power company turn on their auxiliary nuclear generator.
Wow! Look at that house has some serious Christmas lights on it!