This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. The amount that a teacup can hold.

n. A unit of measure, the capacity or volume of a teacup.

n. As much as a teacup can hold; enough to fill a teacup.

n. As much as a tea-cup will hold; as a definite quantity, four fluidounces, or one gill.

n. as much as a teacup will hold

"He went into the kitchen and swallowed nearly a teacupful of Victory Gin."

containerful   

tablespoonful    dessert-spoonful    gill    teacup    coffeecupful    cupful    spoonsful    pint    wineglassful    seasoning