'Cold wave' definitions:

Definition of 'cold wave'

From: WordNet
noun
A wave of unusually cold weather

Definition of 'Cold wave'

From: GCIDE
  • Cold wave \Cold" wave"\ (Meteor.) In the terminology of the United States Weather Bureau, an unusual fall in temperature, to or below the freezing point, exceeding 16[deg] in twenty-four hours or 20[deg] in thirty-six hours, independent of the diurnal range. [Webster 1913 Suppl.]

Synonyms of 'cold wave'

From: Moby Thesaurus