'parsec' definitions:

Definition of 'parsec'

From: WordNet
noun
A unit of astronomical length based on the distance from Earth at which stellar parallax is 1 second of arc; equivalent to 3.262 light years [syn: parsec, secpar]

Definition of 'parsec'

From: GCIDE
  • parsec \par"sec\ (p[aum]r"s[e^]k), 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]