extremely low frequency

noun

, Radio.

1. any frequency between 30 and 300 hertz. : ELF, elf

extremely low frequency

noun

1. a radio frequency or radio-frequency band below 3 kilohertz ELF

Word History and Origins

Origin of extremely low frequency¹

First recorded in 1965–70

Example Sentences

The emissions fluctuate over time and produce an extremely low frequency signal that travels great distances. allowing sensors to help identify the submarines.

From Washington Times

In the United States, on one hand we have high frequency trading, but once those trades are filled, we have extremely low frequency clearing and settlement systems.

From Time

Mr. Alexis, a former sailor, left behind a document accusing the Navy of attacking his brain with “extremely low frequency” electromagnetic waves.

From New York Times

"ELF" is believed to stand for "extremely low frequency."

From Reuters

During a press conference, the agency said that Aaron Alexis, 34, had believed he was being controlled by extremely low frequency radio waves.

From BBC