The crossword solutions for the term DINER CUPFUL are JOE, which is a 3 letter word. JOE is a common nickname for Joseph, which is a name of Hebrew origin meaning 'God will increase'. It is also a popular name in many cultures and is often used as a title for a man or boy. In the context of the term DINER CUPFUL, JOE could refer to a diner cupful of coffee, which is a popular beverage served in diners.