The Collaborative International Dictionary of English v.0.48:

Ram \Ram\ (r[a^]m), n. [AS. ramm, ram; akin to OHG. & D. ram,
   Prov. G. ramm, and perh. to Icel. ramr strong.]
   1. The male of the sheep and allied animals. In some parts of
      England a ram is called a tup.
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   2. (Astron.)
      (a) Aries, the sign of the zodiac which the sun enters
          about the 21st of March.
      (b) The constellation Aries, which does not now, as
          formerly, occupy the sign of the same name.
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   3. An engine of war used for butting or battering.
      Specifically:
      (a) In ancient warfare, a long beam suspended by slings in
          a framework, and used for battering the walls of
          cities; a battering-ram.
      (b) A heavy steel or iron beak attached to the prow of a
          steam war vessel for piercing or cutting down the
          vessel of an enemy; also, a vessel carrying such a
          beak.
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   4. A hydraulic ram. See under Hydraulic.
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   5. The weight which strikes the blow, in a pile driver, steam
      hammer, stamp mill, or the like.
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   6. The plunger of a hydraulic press.
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   Ram's horn.
      (a) (Fort.) A low semicircular work situated in and
          commanding a ditch. [Written also ramshorn.]
          --Farrow.
      (b) (Paleon.) An ammonite.
          [1913 Webster]