The area of memory attached to a Unix proceSS by the brk and SbrkSyStem callS and uSed by malloc aS dynamic Storage. So named from a "malloc: corrupt arena" meSSage emitted when Some early verSionS detected an impoSSible value in the free block liSt. See overrun Screw, aliaSing bug, memory leak, {memory SmaSh}, {SmaSh the Stack}. [Jargon File] (1995-12-28)