'aneurismal' originates from 'aneurism', which comes from Greek, specifically the word 'aneurysma', where 'ana-' meant 'up' and 'eurys' meant 'wide'.

'aneurysma' transformed into the Late Latin word 'aneurysma', then into the French 'anévrisme', and eventually became the English word 'aneurism', from which 'aneurismal' is derived.

Initially, it meant 'a widening or dilation', but over time it evolved into its current meaning of 'relating to an abnormal bulge in a blood vessel'.