Also found in: Thesaurus, Encyclopedia, Wikipedia.
Switch to new thesaurus
|Noun||1.||D-layer - the lowest region of the ionosphere (35 to 50 miles up) that reflects low-frequency radio waves|
ionosphere - the outer region of the Earth's atmosphere; contains a high concentration of free electrons
Based on WordNet 3.0, Farlex clipart collection. © 2003-2012 Princeton University, Farlex Inc.