'ball-shaped' originates from Modern English, a compound of the noun 'ball' and the adjective-forming element '-shaped'. 'ball' ultimately comes from Old Norse 'bǫllr' meaning 'ball', and 'shape' comes from Old English 'gesceap' meaning 'form'.

'ball' changed from Old Norse 'bǫllr' to Middle English 'ball' and eventually entered Modern English compounds such as 'ball-shaped'. 'shape' developed from Old English 'gesceap' (sense 'form') through Middle English to Modern English 'shape', which produced the productive suffix '-shaped'.

Initially, it literally meant 'having the form of a ball'; over time this literal meaning has remained essentially unchanged and is still used to describe spherical or near-spherical forms.