The Collaborative International Dictionary of English v.0.48:

Danger \Dan"ger\, n. [OE. danger, daunger, power, arrogance,
   refusal, difficulty, fr. OF. dagier, dongier (with same
   meaning), F. danger danger, fr. an assumed LL. dominiarium
   power, authority, from L. dominium power, property. See
   Dungeon, Domain, Dame.]
   1. Authority; jurisdiction; control. [Obs.]
      [1913 Webster]

            In dangerhad he . . . the young girls. --Chaucer.
      [1913 Webster]

   2. Power to harm; subjection or liability to penalty. [Obs.]
      See In one's danger, below.
      [1913 Webster]

            You stand within his danger, do you not? --Shak.
      [1913 Webster]

            Covetousness of gains hath brought [them] in
            dangerof this statute.                --Robynson
                                                  (More's
                                                  Utopia).
      [1913 Webster]

   3. Exposure to injury, loss, pain, or other evil; peril;
      risk; insecurity.
      [1913 Webster]

   4. Difficulty; sparingness. [Obs.] --Chaucer.
      [1913 Webster]

   5. Coyness; disdainful behavior. [Obs.] --Chaucer.
      [1913 Webster]

   In one's danger, in one's power; liable to a penalty to be
      inflicted by him. [Obs.] This sense is retained in the
      proverb, "Out of debt out of danger."
      [1913 Webster]

            Those rich man in whose debt and danger they be not.
                                                  --Robynson
                                                  (More's
                                                  Utopia).

   To do danger, to cause danger. [Obs.] --Shak.

   Syn: Peril; hazard; risk; jeopardy.

   Usage: Danger, Peril, Hazard, Risk, Jeopardy.
          Danger is the generic term, and implies some
          contingent evil in prospect. Peril is instant or
          impending danger; as, in peril of one's life. Hazard
          arises from something fortuitous or beyond our
          control; as, the hazard of the seas. Risk is doubtful
          or uncertain danger, often incurred voluntarily; as,
          to risk an engagement. Jeopardy is extreme danger.
          Danger of a contagious disease; the perils of
          shipwreck; the hazards of speculation; the risk of
          daring enterprises; a life brought into jeopardy.
          [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Danger \Dan"ger\, v. t.
   To endanger. [Obs.] --Shak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

danger
    n 1: the condition of being susceptible to harm or injury; "you
         are in no danger"; "there was widespread danger of disease"
         [ant: safety]
    2: a venture undertaken without regard to possible loss or
       injury; "he saw the rewards but not the risks of crime";
       "there was a danger he would do the wrong thing" [syn:
       risk, peril, danger]
    3: a cause of pain or injury or loss; "he feared the dangers of
       traveling by air"
    4: a dangerous place; "He moved out of danger"

Moby Thesaurus II by Grady Ward, 1.0:

42 Moby Thesaurus words for "danger":
   dangerous ground, desultoriness, emergency, exigency, hazard,
   in danger of, infirmity, insecurity, insolidity, instability,
   insubstantiality, jeopardy, menace, pass, peril, perilousness,
   precariousness, precipice, risk, riskiness, shakiness, shiftiness,
   shiftingness, slipperiness, speculativeness, thin ice, threat,
   ticklishness, treacherousness, treachery, unauthenticity,
   unauthoritativeness, undependability, unfaithworthiness,
   unreliability, unsolidity, unsoundness, unsteadfastness,
   unsteadiness, unsubstantiality, unsureness, untrustworthiness



The Devil's Dictionary (1881-1906):

DANGER, n.

    A savage beast which, when it sleeps,
        Man girds at and despises,
    But takes himself away by leaps
        And bounds when it arises.
                                                          Ambat Delaso