The term "sacred cow" is commonly used to describe something that is considered untouchable or immune from criticism. However, there are several synonyms that can be used in its place. One of these is "taboo topic", which refers to a subject that people are reluctant to discuss or criticize. Another synonym is "off-limits" which indicates that a certain subject or topic is strictly prohibited or cannot be touched upon. Another term that can be used instead of "sacred cow" is "untouchable", which indicates something that is not to be questioned or touched. Regardless of the alternative, it is important to remember that it is necessary to question and criticize to challenge and learn.