the GNU version of the Collaborative International Dictionary of English
adj. Of or pertaining to a parallax.
The Century Dictionary and Cyclopedia
Of, pertaining to, of the nature of, or characterized by parallax.
The angle between the vertical circle and the declination circle of a star.
Word Usage
"Four hundred years ago, he realized that if Copernicus was right—that the Earth orbits the Sun—they could show it by observing the 'parallactic motion' of the nearest stars."