Steward

Stewards are an exclusive, restrictive user group of select wiki people on some specific MediaWiki-powered wiki sites.

Wikimedia Foundation

On Wikimedia Foundation (WMF) wikis, stewards are very specific global administrators across all WMF wikis and projects of the Wikimedia Foundation, as far as their technical abilities go. They are not supposed to use their privileges, unless requested by the local communities. They have their own private wiki, the Wikimedia Steward Wiki. For further information, see the Stewards page on the Wikimedia Meta-Wiki.

ShoutWiki

In respect of the ShoutWiki wiki farm, stewards are the founding bureaucrats of ShoutWiki sites, with the ability to edit all user rights.