The Collaborative International Dictionary of English v.0.48:

Grunt \Grunt\ (gr[u^]nt), v. t. [imp. & p. p. Grunted; p. pr.
   & vb. n. Grunting.] [OE. grunten; akin to As. grunian, G.
   grunzen, Dan. grynte, Sw. grymta; all prob. of imitative; or
   perh. akin to E. groan.]
   To make a deep, short noise, as a hog; to utter a short groan
   or a deep guttural sound.
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         Who would fardels bear,
         To grunt and sweat under a weary life.   --Shak.
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   Grunting ox (Zool.), the yak.
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The Collaborative International Dictionary of English v.0.48:

Ox \Ox\ ([o^]ks), n.; pl. Oxen. [AS. oxa; akin to D. os. G.
   ochs, ochse, OHG. ohso, Icel. oxi, Sw. & Dan. oxe, Goth.
   a['u]hsa, Skr. ukshan ox, bull; cf. Skr. uksh to sprinkle.
   [root]214. Cf. Humid, Aurochs.] (Zool.)
   The male of bovine quadrupeds, especially the domestic animal
   when castrated and grown to its full size, or nearly so. The
   word is also applied, as a general name, to any species of
   bovine animals, male and female.
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         All sheep and oxen, yea, and the beasts of the field.
                                                  --Ps. viii. 7.
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   Note: The castrated male is called a steer until it attains
         its full growth, and then, an ox; but if castrated
         somewhat late in life, it is called a stag. The male,
         not castrated, is called a bull. These distinctions are
         well established in regard to domestic animals of this
         genus. When wild animals of this kind are spoken of, ox
         is often applied both to the male and the female. The
         name ox is never applied to the individual cow, or
         female, of the domestic kind. Oxen may comprehend both
         the male and the female.
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   Grunting ox (Zool.), the yak.

   Indian ox (Zool.), the zebu.

   Javan ox (Zool.), the banteng.

   Musk ox. (Zool.) See under Musk.

   Ox bile. See Ox gall, below.

   Ox gall, the fresh gall of the domestic ox; -- used in the
      arts and in medicine.

   Ox pith, ox marrow. [Obs.] --Marston.

   Ox ray (Zool.), a very large ray (Dicerobatis Giornae) of
      Southern Europe. It has a hornlike organ projecting
      forward from each pectoral fin. It sometimes becomes
      twenty feet long and twenty-eight feet broad, and weighs
      over a ton. Called also sea devil.

   To have the black ox tread on one's foot, to be
      unfortunate; to know what sorrow is (because black oxen
      were sacrificed to Pluto). --Leigh Hunt.
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The Collaborative International Dictionary of English v.0.48:

Yak \Yak\ (y[a^]k), n. [Tibetan gyag.] (Zool.)
   A bovine mammal (Poephagus grunnies) native of the high
   plains of Central Asia. Its neck, the outer side of its legs,
   and its flanks, are covered with long, flowing, fine hair.
   Its tail is long and bushy, often white, and is valued as an
   ornament and for other purposes in India and China. There are
   several domesticated varieties, some of which lack the mane
   and the long hair on the flanks. Called also chauri gua,
   grunting cow, grunting ox, sarlac, sarlik, and
   sarluc.
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   Yak lace, a coarse pillow lace made from the silky hair of
      the yak.
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