medical Definition of berry aneurysm
: an aneurysm of a cerebral artery that resembles a berry or sac in shape and typically occurs at an arterial junction in the circle of Willis
- The culprit is a berry aneurysm, a slight (one-eighth to one-third of an inch) ballooning of the artery in the circle of Willis …
- —Tony Dajer, Discover, March 2009
