Definitions for "Delta wave"
Slowest of the brain's waves, associated with deep sleep.
the normal brainwave in the encephalogram of a person in deep dreamless sleep; occurs with high voltage and low frequency (1 to 4 hertz)
a type of brain wave that is large (high amplitude) and slow (low frequency), and is most often associated with Slow Wave Sleep (stages 3 and 4; often referred to as deep sleep).