GNU Collaborative International Dictionary of English

Found one definition

1.       
   parsec , n. [From parallax second.  See parallax second and annual parallax, under parallax.] (Astron.) A unit of length used in describing astronomical distances, equal to 3.26 light years, or 3.086 x 1013 km.  Abbreviated pc.  The derived units of kiloparsec (kpc, 1000 parsecs) and megaparsec (mpc, one million parsecs) are often found in discussion of astronomical distances.
   PJC