Soi-disant is a French expression meaning purported or self-styled. There are several synonyms that can be used in place of this term. Some of these synonyms include supposed, alleged, self-proclaimed, professed, so-called, and self-acclaimed. All of these words have a similar meaning to soi-disant and can be used interchangeably in many contexts. They are often used to describe someone who claims to have a certain identity or status, but whose claims are not wholly accepted by others. Whether you choose to use soi-disant or one of these synonyms is up to you, but either way, they all convey the same message.