There are a few synonyms that can be used instead of the word "excrutiating". One synonym for excrutiating is "agonizing", which refers to intense, unbearable pain. Another synonym is "tormenting", which suggests prolonged and persistent pain or discomfort. Similarly, "torturous" can be used to describe an especially difficult or painful experience. Other synonyms include "harsh", "severe", "intense", and "grueling". It is important to note that while these words may be used interchangeably, they often have slightly different connotations and shades of meaning, so it's important to choose the best word for the specific context.