The Collaborative International Dictionary of English v.0.48:

Levy \Lev"y\ (-[y^]), n.; pl. Levies (-[i^]z). [A contr. of
   elevenpence or elevenpenny bit.]
   A name formerly given in Pennsylvania, Maryland, and Virginia
   to the Spanish real of one eighth of a dollar (or 121/2
   cents), valued at eleven pence when the dollar was rated at
   7s. 6d.
   [1913 Webster]