When a particular item or service is not required by the public, it can be described as "not in demand". There are various synonyms that can be used to indicate the same meaning. For instance, the term "unpopular" is commonly used to describe something that is not in demand. "Unsought" is another option that reflects the same notion. Additionally, "unwanted", "unneeded", "unnecessary", and "undesirable" can also be used to describe something that is not in demand. It's important to note that using any of these synonyms can enhance the vocabulary and improve writing skills for clearer communication.