As an English native, I'd rather see proper nouns in a dictionary before seeing "compound words".

Personally, I don't agree that "boiling water" is a word (with a space) - I would refer to it as a phrase if it had specific meaning, but it just seems like an ordinary pairing of adjective and noun. Also, if a word can contain a space, then what is the meaning of "words" as there doesn't seem an easy way to distinguish between a "compound word" and a common phrase. Is "barking dog" a pair of words, a compound word or a phrase? (It's a pair of words in my mind)