Search Result for "d-layer": 
Wordnet 3.0

NOUN (1)

1. the lowest region of the ionosphere (35 to 50 miles up) that reflects low-frequency radio waves;
[syn: D-layer, D region]



The Collaborative International Dictionary of English v.0.48:

D-layer \D-layer\ n.
   the lowest region of the ionosphere (35 to 50 miles up) that
   reflects low-frequency radio waves.

   Syn: D region.
        [WordNet 1.5]


WordNet (r) 3.0 (2006):

D-layer
    n 1: the lowest region of the ionosphere (35 to 50 miles up)
         that reflects low-frequency radio waves [syn: D-layer, D
         region]