Grammar with your cup of good morning america? “Coffeehouse” or “coffee-house”:
The examples in the online version of the Oxford English Dictionary (subscription required) are from 1876 and earlier and they all show the word hyphenated. The entries in the Merriam-Webster online dictionary and Dictionary.com, on the other hand, list only “coffeehouse.” The American Heritage Dictionary of the English Language entry at Dictionary.com also shows the open compound as an alternative (coffee house).
I decided to go with “coffeehouse.” Looking at the dictionary entries was a great reminder of how complicated compound words can be and how their formatting can change over time. If you’re not sure whether a word is an open compound, closed compound, or hyphenated compound, the only thing you can do is pick a dictionary and go with its recommendation.