
Cupful
Measurement Unit
A 'cupful' refers to a fixed unit of measure in recipes, equivalent to 8 fluid ounces in the US. 
Exactness Varies
'Cupful' can imply precision in baking but can be approximate in everyday language. 
Non-Liquid Use
Although 'cupful' often relates to liquids, it's also used for solids like flour or sugar. 