Source : Webster's Revised Unabridged Dictionary (1913)

Plagiary \Pla"gia*ry\, n.; pl. {Plagiaries}. [L. plagiarius a
   kidnaper, a literary thief, fr. plagium kidnaping; cf. plaga
   a net, perh. akin to E. plait: cf. F. plagiaire.]
   1. A manstealer; a kidnaper. [Obs.]

   2. One who purloins another's expressions or ideas, and
      offers them as his own; a plagiarist. --Dryden.

   3. Plagiarism; literary thief. --Milton.