The Collaborative International Dictionary of English v.0.48:

East \East\ ([=e]st), n. [OE. est, east, AS. e['a]st; akin to D.
   oost, oosten, OHG. [=o]stan, G. ost, osten, Icel. austr, Sw.
   ost, Dan. ["o]st, ["o]sten, Lith. auszra dawn, L. aurora (for
   ausosa), Gr. 'hw`s, "e`os, 'a`yws, Skr. ushas; cf. Skr. ush
   to burn, L. urere. [root]149, 288. Cf. Aurora, Easter,
   Sterling.]
   1. The point in the heavens where the sun is seen to rise at
      the equinox, or the corresponding point on the earth; that
      one of the four cardinal points of the compass which is in
      a direction at right angles to that of north and south,
      and which is toward the right hand of one who faces the
      north; the point directly opposite to the west.
      [1913 Webster]

            The east began kindle.                --E. Everett.
      [1913 Webster]

   2. The eastern parts of the earth; the regions or countries
      which lie east of Europe; the orient. In this indefinite
      sense, the word is applied to Asia Minor, Syria, Chaldea,
      Persia, India, China, etc.; as, the riches of the East;
      the diamonds and pearls of the East; the kings of the
      East.
      [1913 Webster]

            The gorgeous East, with richest hand,
            Showers on her kings barbaric pearl and gold.
                                                  --Milton.
      [1913 Webster]

   3. (U. S. Hist. and Geog.) Formerly, the part of the United
      States east of the Alleghany Mountains, esp. the Eastern,
      or New England, States; now, commonly, the whole region
      east of the Mississippi River, esp. that which is north of
      Maryland and the Ohio River; -- usually with the definite
      article; as, the commerce of the East is not independent
      of the agriculture of the West.
      [1913 Webster]

   East by north, East by south, according to the notation
      of the mariner's compass, that point which lies 111/4[deg]
      to the north or south, respectively, of the point due
      east.

   East-northeast, East-southeast, that which lies
      221/2[deg] to the north or south of east, or half way
      between east and northeast or southeast, respectively. See
      Illust. of Compass.
      [1913 Webster]

WordNet (r) 3.0 (2006):

east by south
    n 1: the compass point that is one point south of due east [syn:
         east by south, EbS]