The term 'unestablished' refers to something that hasn't yet gained recognition or approval from the society or higher authorities. There are several synonyms that can be used instead of unestablished such as novel, untested, untried, unproven, unconventional, and experimental. These words describe the same concept of something that is still in its early stages of development, with no surety of success. The term 'unfounded' can also be used to convey a sense of uncertainty and lack of credibility. It is important to note that while these words can be used interchangeably, they have slightly different connotations and should be used appropriately depending on the context in which they are being used.