The English language is a fickle beast, and we don't make it any easier by having words with multiple meanings and making different words mean the same thing. Case in point; dinner, supper, or lunch?

Dinner was always the evening meal in my house (breakfast, lunch, dinner...that was it), but my grandma called it supper, while one of my best friend's mom called what I thought was dinner, lunch. Very confusing.

There aren't really any wrong answers here. Check this out from Wikipedia:

Supper is a name for the evening meal in some dialects of English. While often used interchangeably with "dinner" today, supper was traditionally a separate meal. "Dinner" traditionally had been used to refer to the main and most formal meal of the day, which, from the Middle Ages until the 18th century, was most often the midday meal. When the evening meal became the main meal, it was referred to as "dinner", and the lighter midday meal was called "luncheon."

Picture by randomduck, Flickr.