VERB (3)

1. belittle through talk;

2. speak in a condescending manner, as if to a child;
- Example: "He talks down to her"

3. direct and control (the flight of an airplane during landing) via radio;
- Example: "the control tower talked down the plane whose pilot fell ill"

WordNet (r) 3.0 (2006):

talk down
    v 1: belittle through talk
    2: speak in a condescending manner, as if to a child; "He talks
       down to her"
    3: direct and control (the flight of an airplane during landing)
       via radio; "the control tower talked down the plane whose
       pilot fell ill"

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "talk down":
   alight, come down, come in, crash-land, descend, ditch, downwind,
   filibuster, land, level off, light, outlast, outspeak, outtalk,
   overshoot, pancake, settle down, touch down, upwind