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An onset of unusually cold weather within a 24-hour period.
1. (Physical Geography) meteorol a sudden spell of low temperatures over a wide area, often following the passage of a cold front
2. (Hairdressing & Grooming) hairdressing a permanent wave made by chemical agents applied at normal temperatures
1. a rapid and considerable drop in temperature, usu. affecting a large area.
2. a permanent wave set in the hair by chemical solutions without the aid of heat.