This is a classic mashup word, or more technically a "portmanteau word." (Portmanteau once meant suitcase; such words stuff two words into one word.)
Brunch (breakfast + lunch) was first used in 1896, and now even the French say it. Its success has inspired many other attempts to blend mealtimes.
For example: Care for some linner or lupper?
These other mashups haven't caught on, probably because unlike brunch the meals they describe remain mostly hypothetical.