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1.
A mix of mustard and ketchup accidentally/purposefully mixed on food
guy 1-awww, now theres kustard on my wiener.
guy 2-then why did u get mustard and ketchup u idiot if u knew they were gonna mix!
by David the gangster July 28, 2008
 
2.
Mixture of ketchup and mustard.
"So, it's a nice orange color. Ketchup and mustard make kustard."

"I put kustard on my mini-hot dogs most of the time."

"Kustard tastes great on corndogs."
by Katie Marie Bell October 05, 2011