This word is not acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. the collective trade name for a type of plastic food-storage container with a translucent bottom and a close-fitting lid designed to seal the container tightly. It is in common use in the late 20th century and early 21st century in the U. S. It comes in a variety of shapes and sizes, suitable for storing a variety of items. Also used attributively.

"There is no recipe for this one, just a joining of all the ingredients you have tucked in tupperware in your fridge - with a bit of mayo, salt and pepper."

tupper ware