'armload' is a compound formed from 'arm' + 'load'; 'arm' comes from Old English 'earm' meaning 'arm', and 'load' comes from Old English 'lād' meaning 'way, course' and later 'burden'.

The compound developed in post-Middle English/early Modern English by joining the words 'arm' and 'load' to describe a burden carried in the arms; it has remained recognizable as the modern word 'armload'.

Initially it referred specifically to a burden that could be carried in the arms; over time it has also been used figuratively to mean 'a large amount'.