'scoopful' originates from Modern English, formed by adding the suffix '-ful' to the noun 'scoop', where 'scoop' referred to a ladle or a cup-like implement for scooping.

'scoop' comes into English from Middle English 'scole'/'scoop(e)', ultimately from Old Norse 'skopa' meaning 'cup' or 'ladle'; adding '-ful' produced 'scoopful' in later English to mean 'the amount a scoop holds'.

Initially the root referred to a physical ladle or cup ('a scooping implement'), and over time compounds like 'scoopful' came to mean specifically 'the amount taken by that scooping implement' (a measured serving).