Defn: One afflicted with color blindness.
DALTONISM
Dal"ton*ism, n.
Defn: Inability to perceive or distinguish certain colors, esp. red; color blindness. It has various forms and degrees. So called from the chemist Dalton, who had this infirmity. Nichol.
DAM
Dam, n. Etym: [OE. dame mistress, lady; also, mother, dam. See Dame.]
1. A female parent; — used of beasts, especially of quadrupeds; sometimes applied in contempt to a human mother. Our sire and dam, now confined to horses, are a relic of this age (13th century) . . . .Dame is used of a hen; we now make a great difference between dame and dam. T. L. K. Oliphant. The dam runs lowing up end down, Looking the way her harmless young one went. Shak.
2. A kind or crowned piece in the game of draughts.
DAM Dam, n. Etym: [Akin to OLG., D., & Dan. dam, G. & Sw. damm, Icel. dammr, and AS. fordemman to stop up, Goth. Faúrdammjan.]
1. A barrier to prevent the flow of a liquid; esp., a bank of earth, or wall of any kind, as of masonry or wood, built across a water course, to confine and keep back flowing water.
2. (Metal.)
Defn: A firebrick wall, or a stone, which forms the front of the hearth of a blast furnace. Dam plate (Blast Furnace), an iron plate in front of the dam, to strengthen it.