from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A unit of astronomical length based on the distance from Earth at which stellar parallax is one second of arc and equal to 3.258 light-years, 3.086 × 1013 kilometers, or 1.918 × 1013 miles.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. parallax second
from the GNU version of the Collaborative International Dictionary of English
- n. 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.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. 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
par(allax) + sec(ond)1.(American Heritage® Dictionary of the English Language, Fourth Edition)
Contraction of parallax second. (Wiktionary)