The Collaborative International Dictionary of English v.0.48:

Water buck \Wa"ter buck`\ (Zool.)
   A large, heavy antelope (Kobus ellipsiprymnus) native of
   Central Africa. It frequents the banks of rivers and is a
   good swimmer. It has a white ring around the rump. Called
   also photomok, water antelope, and waterbok.
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   Note: The name is also applied to other related species, as
         the leche (Kobus leche), which has similar habits.
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The Collaborative International Dictionary of English v.0.48:

Buck \Buck\ (b[u^]k), n. [OE. buk, bucke, AS. bucca, bua,
   he-goat; akin to D. bok, OHG. pocch, G. bock, Ir. boc, W.
   bwch, Corn. byk; cf. Zend b[=u]za, Skr. bukka. [root]256. Cf.
   Butcher, n.]
   1. The male of deer, especially fallow deer and antelopes, or
      of goats, sheep, hares, and rabbits.
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   Note: A male fallow deer is called a fawn in his first year;
         a pricket in his second; a sorel in his third; a sore
         in his fourth; a buck of the first head in his fifth;
         and a great buck in his sixth. The female of the fallow
         deer is termed a doe. The male of the red deer is
         termed a stag or hart and not a buck, and the female is
         called a hind. --Brande & C.
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   2. A gay, dashing young fellow; a fop; a dandy.
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            The leading bucks of the day.         --Thackeray.
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   3. A male Indian or negro. [Colloq. U.S.]
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   Note: The word buck is much used in composition for the names
         of antelopes; as, bush buck, spring buck.
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   Blue buck. See under Blue.

   Water buck, a South African variety of antelope (Kobus
      ellipsiprymnus). See Illust. of Antelope.
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