n. 秒差距(天体距离单位)

[ 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
<noun.quantity>

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]