Teaspoonful is from teaspoon (tea + spoon) + -ful. Tea is ultimately from Min Chinese tê; spoon is from Old English spōn ('chip of wood'). Important recorded forms include tê (Chinese) and spōn (Old English). Morphologically, -ful marks possession, abundance, or tendency, so the word names something characterized by the base idea. The modern sense continues the older lexical line without requiring a separate origin. In current use it covers the amount that a teaspoon holds, used as a measure. The wider family includes related words such as teaspoon, spoon, spoonful, and tablespoonful.