A unit of capacity equal to the amount a teaspoon can hold which is taken approximately as 5ml. (noun)
Examples of word teaspoonful
Trying to swallow them by the teaspoonful is another -- and, let me say from the get-go, not an advisable -- thing altogether.
_ -- Soak a teaspoonful of gelatine in a dessert spoonful of water.
Soak a teaspoonful of gelatine one or two hours in three table - spoonfuls of water.
Exactly the same amount of water, to the ounce, or even the teaspoonful, that is poured into the boiler of an engine, is given off through its funnel and escape-pipes in the form of steam; and precisely the same amount of water which we pour into our stomachs will reappear on the surface of the body again in the form of the vapor from the lungs, the perspiration from the skin, and the water from the kidneys.
The way to test was to get a bowl of cold water and drop half a teaspoonful of mixture into it, leaving it to cool for a minute.