- an air mass of high temperature covering an extended area and moving relatively slowly.
- a period of abnormally hot and usually humid weather.
Origin of heat wave
First recorded in 1875–80
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Examples from the Web for heat wave
We were in a furnace—a heat-wave in which we were like to drown.Hesperothen; Notes from the West, Vol. 1 (of 2)
W. H. Russell
The first touched upon an untimely, although welcome, heat-wave.Adventures and Enthusiasms
E. V. Lucas
The heat-wave had put forward the almanac, and the Newport season was in full swing nearly a month in advance of its usual date.The Terms of Surrender
Because, five weeks later, there was a heat-wave in the Red Sea, and everybody took off all the clothes they had.Just So Stories
- a continuous spell of abnormally hot weather
- (not in technical use) an extensive slow-moving air mass at a relatively high temperature
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012