'unsustainability' originates from the prefix 'un-' meaning 'not' and the word 'sustainability', which comes from the Latin word 'sustinere', where 'sub-' meant 'up from below' and 'tenere' meant 'to hold'.

'sustainability' evolved from the Latin 'sustinere' through Old French 'soustenir', eventually becoming the modern English word 'sustainability'. The prefix 'un-' was added to form 'unsustainability'.

Initially, 'sustainability' meant 'to hold up or support', but over time it evolved into its current meaning of 'maintaining ecological balance'. 'Unsustainability' denotes the opposite.