dog star Meaning, Definition & Usage

  1. noun the brightest star in the sky; in Canis Major
    Sothis; Sirius; Canicula.

WordNet

Dog" Star`
Definitions
  1. Sirius, a star of the constellation Canis Major, or the Greater Dog, and the brightest star in the heavens; -- called also Canicula, and, in astronomical charts, α Canis Majoris. See Dog days.

Webster 1913