Definition of "rubican"

rubican

adjective
not comparable
1. (rare, of a horse) Coloured mostly red, bay, or black, with flecks of white or grey especially on the flanks.
  Quotations
  There are other mixt kind of colours, such as the Rubican; which is when a black or sorrel Horse hath white Hairs here and there scattered upon his Body, but especially upon his Flanks.
  1729, Jacques de Solleysel, translated by William Hope, The Compleat Horseman: or, Perfect Farrier, page 65
  The grayish and the flea-bitten differ from the rubican, in that the white hairs which form these markings are sufficiently numerous to change, locally, the nature of the base of the coat.
  1904, Armand Goubaux, Gustave Barrier, translated by Simon J.J. Harger, The Exterior of the Horse, page 788
  When both parents are brown, foals may be of any colour, also gray if one parent is rubican. The majority of foals, however, will likewise be brown.
  1909, Burchard von Oettingen, Horse Breeding in Theory and Practice, page 331