F layer

noun

: the highest and most densely ionized regular layer of the ionosphere occurring at night within the F region

Word History

First Known Use

1928, in the meaning defined above

Time Traveler

The first known use of F layer was in 1928

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flay

F layer

flayflint

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Cite this Entry

Style

“F layer.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/F%20layer. Accessed 31 Oct. 2025.

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Kids Definition

F layer

noun

: the highest and most highly charged layer of the ionosphere

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