'unfeasibly' originates from the word 'unfeasible', which is derived from the prefix 'un-' meaning 'not' and 'feasible', which comes from the Latin word 'facere', meaning 'to do or make'.

'unfeasible' evolved from the Old French word 'faisable', which meant 'that may be done', and eventually became the modern English word 'feasible'.

Initially, 'feasible' meant 'capable of being done', and 'unfeasible' has retained the meaning of 'not capable of being done'.