"Hey Travis. You hungry?"
"No, dude, I already had dunchfast and now I've got to go throw up out of my butt!"
"Gross, thanks for the info. I'm going to have my girlfriend give me a blumpkin."
The meal that comes between Dinner and Breakfast. Brunch is the meal between Breakfast and Lunch. Since Breakfast comes first, it is used as the first part of the word and since lunch comes second, it is used as the second part of the word.