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The ritual and future holiday of going out to Costco for lunch every Thursday.
Every Thursday, me and my friends go out to Costco for lunch. While there, we feast upon the delicious Costco pizza and some of the many awesome food samples that are offered.

"Hey dude, it's Costco Thursday." - Jake
"Shizzle! I can't wait to get me some Costco pizza!" - Bill
by KielbasaKing February 12, 2009
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