'unequally-related' originates from the combination of 'unequal' and 'related', where 'un-' is a prefix meaning 'not', 'equal' comes from Latin 'aequalis' meaning 'even, level', and 'related' is derived from Latin 'relatus', the past participle of 'referre' meaning 'to bring back'.

'unequal' changed from the Old French word 'inequal', and 'related' evolved from the Latin 'relatus', eventually forming the modern English term 'unequally-related'.

Initially, 'unequal' meant 'not equal in quantity or quality', and 'related' meant 'connected by a relationship'. The combined term 'unequally-related' now specifically refers to relationships lacking equality.