parsec

• POS: Noun
• HYPHEN: par=sec

CIDE DICTIONARY

parsec, n. [From parallax second. See parallax second and annual parallax, under parallax.].

 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]

OXFORD DICTIONARY

parsec, n. a unit of stellar distance, equal to about 3.25 light years (3.08 x 10(16) metres), the distance at which the mean radius of the earth's orbit subtends an angle of one second of arc.

Etymology

PARALLAX + SECOND(2)

ROGET THESAURUS

parsec

Length

N length, longitude, span, mileage, distance, line, bar, rule, stripe, streak, spoke, radius, lengthening, prolongation, production, protraction, tension, tensure, extension, line, nail, inch, hand, palm, foot, cubit, yard, ell, fathom, rood, pole, furlong, mile, league, chain, link, arpent, handbreadth, jornada, kos, vara, astronomical unit, AU, light- year, parsec, nanometer, nm, micron, micrometer, millimicron, millimeter, mm, centimeter, cm, meter, kilometer, km, pedometer, perambulator, scale, long, longsome, lengthy, wiredrawn, outstretched, lengthened, sesquipedalian, interminable, no end of, macrocolous, linear, lineal, longitudinal, oblong, as long as my arm, as long as today and tomorrow, unshortened &c (shorten), lengthwise, at length, longitudinally, endlong, along, tandem, in a line, in perspective, from end to end, from stem to stern, from head to foot, from the crown of the head to the sole of the foot, from top to toe, fore and aft.