Meaning of tertium quid

ter•ti•um quid

Pronunciation: (tûr'shē-um kwid' Lat. ter'ti-&oobrevem&sec kwid'), [key]
  1. something related in some way to two things, but distinct from both; something intermediate between two things.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.
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