aneurism

the term originates from the greek 'aneurysma', meaning "a widening," itself derived from 'ana-' (up) and 'eurys' (wide). it entered medical latin as 'aneurysma' and later middle english as 'anewrysm'. the original greek sense of "a widening" directly informs the modern medical definition, which specifies a pathological widening or ballooning of a blood vessel. the morphemic logic of "not wide" is a historical misinterpretation; the correct analysis is "up-widening," describing the abnormal dilation of the vessel wall.

Structure: an (not) + eur (wide) + ism (condition) an- (greek origin, meaning "not" or "without"); eur- (from greek 'eurys', meaning "wide"); -ism (from greek '-ismos', a suffix forming nouns indicating a state or condition).