The Collaborative International Dictionary of English v.0.48:

Classis \Clas"sis\, n.; pl. Classes. [L. See Class, n.]
   1. A class or order; sort; kind. [Obs.]
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            His opinion of that classis of men.   --Clarendon.
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   2. (Eccl.) An ecclesiastical body or judicatory in certain
      churches, as the Reformed Dutch. It is intermediate
      between the consistory and the synod, and corresponds to
      the presbytery in the Presbyterian church.
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