Squillionaire is a term used to describe someone who is incredibly wealthy or has a lot of money. However, there are several other terms that can be used as synonyms for this word. Some examples include billionaire, millionaire, tycoon, magnate, mogul, and fat cat. These terms are commonly used to describe individuals who have amassed a great deal of wealth through various means such as business ventures, investments, or inheritance. While these terms may differ slightly in their connotations, they all refer to individuals who have achieved a level of financial success that is well beyond the average person's means.