dam
The mother of a horse.
dam’s sire (broodmare sire)
The sire of a broodmare. Used in reference to the maternal grandsire of a foal.
dark bay or brown
A horse color that ranges from brown with areas of tan on the shoulders, head and flanks, to a dark brown, with tan areas seen only in the flanks and/or muzzle. The mane, tail and lower portions of the legs are always black unless white markings are present.
distaff
A female horse.