'shapelessly' originates from Old English elements: the noun 'shape' (from Old English 'gesceap' meaning 'form, creation'), plus the suffix '-less' (from Old English '-lēas' meaning 'without'), and the adverbial suffix '-ly' (from Old English '-līċe' meaning 'in the manner of').

'gesceap' became Middle English 'shape'; adding '-less' formed 'shapeless', and with the later addition of '-ly' it developed into the modern adverb 'shapelessly'.

Initially, it meant 'in a manner lacking shape or form'; over time it extended to figurative senses like 'without structure or organization' and uses describing loose, ill-fitting clothing.