The Collaborative International Dictionary of English v.0.48:

Adminicle \Ad*min"i*cle\, n. [L. adminculum support, orig., that
   on which the hand rests; ad + manus hand + dim. ending
   -culym.]
   1. Help or support; an auxiliary. --Grote.
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   2. (Law) Corroborative or explanatory proof.
      [1913 Webster]

   Note: In Scots law, any writing tending to establish the
         existence or terms of a lost deed. --Bell.
         [1913 Webster]