'vaguely-structured' originates from the combination of 'vague' and 'structure', where 'vague' comes from Latin 'vagus' meaning 'wandering' and 'structure' from Latin 'structura' meaning 'a fitting together, building'.

'vague' changed from the Latin word 'vagus' to the Old French 'vague', and eventually became the modern English word 'vague'. 'Structure' evolved from Latin 'structura' to Old French 'structure', and then to modern English 'structure'.

Initially, 'vague' meant 'wandering or uncertain', and 'structure' meant 'a fitting together'. Over time, 'vaguely-structured' evolved to mean 'having an unclear or ill-defined structure'.