root

n. 1. [Unix] The superuser account (with user name root ) that ignores
permission bits, user number 0 on a Unix system. The term avatar is also
used. 2. The top node of the system directory structure; historically the
home directory of the root user, but probably named after the root of an
(inverted) tree. 3. By extension, the privileged system-maintenance login on
any OS. See root mode , go root , see also wheel.

