The term "big freeze" refers to a prolonged period of extremely low temperatures leading to frozen water bodies and disrupted ecosystems. There are several synonyms for this term that can be used interchangeably. The most common alternatives are "deep freeze," "snowstorm," "cold snap," and "ice age." Each of these synonyms conveys a different aspect of the phenomenon. "Deep freeze" suggests the intensity of the cold temperature, while "snowstorm" implies heavy snowfall. "Cold snap" is used to describe a sudden drop in temperature, whereas "ice age" implies a long period of prolonged cold climate. Overall, these synonyms provide a range of descriptive terms that can help convey the severity and duration of a "big freeze".