The origin of the word "sundae" is somewhat debated, but it is often attributed to the late 19th century in the United States. One popular theory suggests that the sundae was created in response to prohibition laws that restricted the sale of soda on Sundays. As a result, soda fountains began serving ice cream topped with syrup (with no soda) to circumvent these restrictions, eventually leading to the creation of what we now know as a sundae. The name itself is thought to be a playful variation of "Sunday," reflecting its association with the day of the week.