delta wave

American  

noun

Physiology.

1. any of the slow brain waves constituting delta rhythm.

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Etymology

Origin of delta wave

First recorded in 1935–40

Example Sentences

During the delta wave, cases began to rise in the UK in June; they rose in the U.S. in July.

From Slate • Oct. 29, 2022

Before the delta wave had even subsided, omicron came roaring in, sickening tens of millions as 2021 turned into 2022.

From Washington Post • Apr. 27, 2022

She says that during the peak delta wave, about 43 percent of cases were reported; during the height of omicron, 26 percent, and now only 7 percent, “which is abysmally low. We are flying blind.”

From Washington Post • Apr. 15, 2022

Even when the delta wave ebbed, the toll continued to rise.

From Washington Times • Apr. 13, 2022

Though fewer people died in Western Washington during last summer’s delta wave, omicron death rates rose here in January this year, specifically in Grays Harbor, Pacific, Cowlitz, Lewis, Thurston, Mason and Pierce counties.

From Seattle Times • Apr. 12, 2022