'unevaluability' originates from Modern English, constructed from the prefix 'un-' and the noun 'evaluability', where 'un-' meant 'not' and 'evaluate' meant 'to determine the value of'.

'unevaluability' was formed in Modern English by adding the negative prefix 'un-' to 'evaluability'. 'Evaluability' derives from 'evaluate' (from French 'évaluer'), which in turn comes from Medieval Latin 'valutare' and ultimately Latin 'valere' meaning 'to be worth' or 'to have value'.

Initially, the root 'evaluate' meant 'to set a value or price'; over time it broadened to mean 'to assess or judge'. 'Unevaluability' has come to mean the inability to assess or judge something.