Definition of "low frequency" []

• A radio frequency in the range from 30 to 300 kilohertz. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• ""Essentially," Harper said, "it's a series of very low frequency radio receivers near the North Pole that listen to the sounds of the earth – plasma wave emissions from the northern lights, broadband pulses from lightning storms, that sort of thing.""
• "Fathoms below, a sickening low frequency rumble resonated upward through the water as the gigantic submerged sheet began scraping its way back up the face of the glacier."