The Collaborative International Dictionary of English v.0.48:

Southeast \South`east"\ (?; by sailors sou"-), n.
   The point of the compass equally distant from the south and
   the east; the southeast part or region.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Southeast \South`east\ (?; by sailors sou"-), a.
   Of or pertaining to the southeast; proceeding toward, or
   coming from, the southeast; as, a southeast course; a
   southeast wind.
   [1913 Webster]

WordNet (r) 3.0 (2006):

south-east
    adv 1: to, toward, or in the southeast [syn: southeast,
           south-east, sou'-east]

Moby Thesaurus II by Grady Ward, 1.0:

91 Moby Thesaurus words for "southeast":
   Dixie, Dixieland, Down East, East, East Coast, Middle Atlantic,
   Middle West, New England, North, North Central region, Northeast,
   Northwest, Pacific Northwest, SE, SE by E, SE by S, SSE, South,
   Southeast, Southwest, Sunbelt, West, West Coast, Yankeeland,
   antarctic, arctic, austral, boreal, cardinal points, compass card,
   compass rose, degrees, east, eastbound, easterly, eastermost,
   eastern, easternmost, eastland, eastward, half points, hyperborean,
   lubber line, meridional, north, northbound, northeast,
   northeasterly, northeastern, northerly, northern, northernmost,
   northland, northward, northwest, northwesterly, northwestern,
   occident, occidental, orient, oriental, quarter points, rhumb,
   south, south-southeast, southbound, southeast by east,
   southeast by south, southeasterly, southeastern, southeastward,
   southeastwardly, southeastwards, southerly, southern, southernmost,
   southward, southwest, southwesterly, southwestern, sunrise, sunset,
   the Coast, west, westbound, westerly, western, westernmost,
   westland, westward, wild West