In American English, "frig" is a colloquial term that is used as a shortened form of "refrigerator." It is used to refer to the appliance used for keeping food and drinks cold and fresh. The term "frig" is informal and somewhat old-fashioned, and it is not as commonly used as the standard terms "refrigerator" or "fridge."
It's important to note that "frig" is a regional and historical variation of "fridge," and it has largely fallen out of use in modern times. The term "fridge" itself is a colloquial abbreviation of "refrigerator" and has become the more widely accepted and prevalent term in contemporary American English.
The usage of "frig" as a short form of "refrigerator" likely dates back several decades, but it has gradually become less common over time. Today, you are more likely to encounter the term "fridge" or "refrigerator" when referring to the appliance that keeps food cold.
Given its informal and somewhat dated nature, you may still encounter the term "frig" in older literature, movies, or in certain regional dialects, but in general, "fridge" and "refrigerator" are the more widely understood and used terms for the appliance in modern American English.