"Sending to Old Nick" is an old-fashioned idiom that refers to sending someone to hell or the devil. There are many synonyms for this phrase that have evolved over time. Some of these synonyms include "sending to the fiery pits," "sending to the depths of hell," "sending to the abyss," "sending to the underworld," and "sending to the netherworld." All of these phrases carry a similar connotation of eternal punishment and damnation. While these phrases may not be as commonly used today, they are still a vivid reminder of the power of language and the enduring influence of historical idioms.