The term "upper crust" refers to the highest social class or wealthy elite. Antonyms for this phrase would include "lower class," "working class," "middle class," "lower-middle class," and "underprivileged." The lower class is generally associated with poverty and a lack of access to resources, while the working class is characterized by those who work manual labor jobs for a living. The middle class is commonly seen as the largest social class and includes professionals and skilled workers who earn a comfortable living. The lower-middle class is sometimes known as the "working poor," while the underprivileged are those who lack access to basic needs like food and housing.