The term ‘Filthy Rich’ was formerly used to discuss someone who was very wealthy, and who possibly became rich via unfair means. Today, the phrase’s meaning has softened a bit, and it is often used to talk about someone who is extremely rich, even if they became wealthy by honest means.
Example in use:?“The preacher and his wife moved into a mansion; suddenly, they’re filthy rich.”
Although the term ‘filthy rich’ can be traced back to a 16th century iteration, the exact phrase was first used during the 1920s, as illustrated in a 1929 edition of an Ohio newspaper called The Lima News in a story discussing the effects of the Great Depression, when many people were forced to sell their homes or starve: “There is a depressed market. If any of our stock-gambling filthy rich want a winter home, now is the time to acquire it.”