Today's Oxford English Dictionary word-of-the-day ("ice master") reminded me of a question that's been on my mind for some time:
What criteria do dictionary-makers use to decide whether a particular noun phrase is something that should have its own dictionary entry?
(Maybe "noun phrase" isn't quite the right term, but I think people will get the point.)
I'm not seeing an obvious pattern for which noun phrases have entries and which don't. I'm guessing it's somehow based on whether the meaning of the phrase is clear and unambiguous from its component words (in which case no entry is needed) but I don't really know.
In the case of the OED in particular, some entries have a section titled "Compounds". So, for example, the Compounds section for the entry for "bar" has "bar-snack" and "bar-stool". This raises yet another question: How do dictionaries decide when to use hyphens in cases like this? But I'm less interested in that question than the criteria for top-level entries.