The Collaborative International Dictionary of English v.0.48:

Precellence \Pre*cel"lence\, Precellency \Pre*cel"len*cy\, n.
   [L. praecellentia, from praecellens, p. pr. of praecellere to
   excel, surpass: cf. OF. precellence.]
   Excellence; superiority. [Obs.] --Sheldon.
   [1913 Webster]