The Collaborative International Dictionary of English v.0.48:

Loom \Loom\ (l[=oo]m), v. i. [imp. & p. p. Loomed (l[=oo]md);
   p. pr. & vb. n. Looming.] [OE. lumen to shine, Icel. ljoma;
   akin to AS. le['i]ma light, and E. light; or cf. OF. lumer to
   shine, L. luminare to illumine, lumen light; akin to E.
   light. [root]122. See Light not dark.]
   1. To appear above the surface either of sea or land, or to
      appear enlarged, or distorted and indistinct, as a distant
      object, a ship at sea, or a mountain, esp. from
      atmospheric influences; as, the ship looms large; the land
      looms high.
      [1913 Webster]

            Awful she looms, the terror of the main. --H. J.
                                                  Pye.
      [1913 Webster]

   2. To rise and to be eminent; to be elevated or ennobled, in
      a moral sense.
      [1913 Webster]

            On no occasion does he [Paul] loom so high, and
            shine so gloriously, as in the context. --J. M.
                                                  Mason.
      [1913 Webster]

   3. To become imminent; to impend.
      [PJC]