Source : Webster's Revised Unabridged Dictionary (1913)

Intrenchment \In*trench"ment\, n. [From {Intrench}.]
   1. The act of intrenching or the state of being intrenched.

   2. (Mil.) Any defensive work consisting of at least a trench
      or ditch and a parapet made from the earth thrown up in
      making such a ditch.

            On our side, we have thrown up intrenchments on
            Winter and Prospect Hills.            --Washington.

   3. Any defense or protection.

   4. An encroachment or infringement.

            The slight intrenchment upon individual freedom.
                                                  --Southey.

Source : WordNet®

intrenchment
     n : an entrenched fortification; a position protected by
         trenches [syn: {entrenchment}]