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)