A lot of people believe the two words mean the same thing, in many parts of the world supper and dinner, are used to refer to the evening meal.
But in some places dinner is the afternoon meal- synonym to lunch while supper serves as the evening meal.
Dinner does not imply the time of the day, and it depends mainly on a person's location; it could mean the afternoon or evening meal, but one thing that is constant of dinner is the fact that it always refers to the primary or most substantial meal of the day.
The etymology of the word dinner comes from the Vulgar Latin word disjējūnāre which means- to break one's fast while supper is connected to the evening and derives its origin from the French word- souper which means- evening meal.
Biblically supper also means evening meal; it was the last meal taken by Jesus Christ before his crucifixion. It is referred to as the Last Supper.
Noah Webster wrote:
“The dinner of fashionable people would be the supper of rustic.”
This statement shows that the word dinner is used to refer to afternoon meals in some rural parts of the country.
But for dinner, if you're invited over, no matter what the time or location may be, always expect an extraordinary meal.
In some parts of the US, dinner and supper are used interchangeably. For example, Kentucky and Virginia refer to evening meals as supper, while places like Maryland and California evening meals are called dinner. Most people believe that the word supper is more of a Southern thing.
It is not necessarily an American South or Midwestern tradition but instead a farming family’s trademark, and this was because Southern and Midwestern states were involved heavily in Agriculture, so supper was the lighter meal of the day while dinner was the more significant, evening food.
According to food historian Helen Zoe Veit, she said in an NPR interview that dinner in the 19th century was an afternoon meal and afternoon meals were the largest, it helped keep the farmers, their employees and family healthy and gave them the energy they needed to remain at their work.
In a recent survey from Google Ngram, the use of the word supper has been reducing since the beginning of the 1900s while the use of lunch has increased. Dinner is more favored by the younger generation and of the three food terms: breakfast, lunch and dinner, dinner is the most widely used.
So when next you're called up for dinner or supper, there won't be any confusion.