Source : Webster's Revised Unabridged Dictionary (1913)

Unique \U*nique"\, a. [F. unique; cf. It. unico; from L. unicus,
   from unus one. See {One}.]
   Being without a like or equal; unmatched; unequaled;
   unparalleled; single in kind or excellence; sole. --
   {U*nique"ly}, adv. -- {U*nique"ness}, n.

Source : WordNet®

uniqueness
     n : the quality of being one of a kind; "that singularity
         distinguished him from all his companions" [syn: {singularity}]