D region

noun

: the lowest part of the ionosphere occurring approximately between 30 and 55 miles (50 and 90 kilometers) above the surface of the earth

Word History

First Known Use

1930, in the meaning defined above

Time Traveler
The first known use of D region was in 1930

Dictionary Entries Near D region

Cite this Entry

“D region.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/D%20region. Accessed 21 Apr. 2024.

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