'bagful' originates from English, specifically the combination of the noun 'bag' and the suffix '-ful', where 'bag' ultimately comes from Old Norse 'baggi' meaning 'sack' and '-ful' comes from Old English 'full' meaning 'full of'.

'bag' changed from Old Norse 'baggi' to Middle English 'bagge' (or 'bag') and eventually became the modern English word 'bag'; the suffix '-ful' developed from Old English 'full' and was later used productively as a suffix to form nouns like 'bagful'.

Initially it literally meant 'full of a bag' (the quantity that fills a bag); over time it has also taken on a figurative sense meaning 'a large amount' or 'a lot'.