This appears to be a misspelling of 'administration'—the management and operation of an organization, business, or government.
This is a common typographical error for 'administration' (from Latin administrare). The misspelling drops the second 'i'.
Interestingly, spell-check systems have had to learn that 'adminstration' is so common in human typing that they should recognize it as a likely typo and suggest 'administration'!
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