root

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}.

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