'armsful' originates from English, specifically the compound of 'arm' and the suffix '-ful', where 'arm' originally meant 'forelimb' and '-ful' meant 'full (of)'.

'armsful' changed from Old English elements (compare Old English 'earm' for 'arm' and Old English 'ful' for 'full') through Middle English compound forms (e.g. 'armful') and eventually became the modern English plural form 'armsful'.

Initially, it meant 'as much as the arm (or arms) can hold'; over time it has retained that sense and is used to denote multiple such loads ('armsful').