what is a parsec
Definition of PARSEC. : a unit of measure for interstellar space that is equal to 3.26 light-years and is the distance to an object having a parallax of one second as seen from points separated by one astronomical unit.ADVERTISEMENT.par allax + sec ond. a unit of measure for interstellar space that is equal to 3.26 light-years and is the distance to an object having a parallax of one second as seen from points separated by one astronomical unit. ADVERTISEMENT.