It depends a lot on what you mean by a language. Iglf you define 'the English language' as 'all of the words that some amount of people who identify as speaking English would understand', then of course there is no dictionary that would cover that (but by this definition, many words in the English language are Indian, Chinese, Romanian, Russian, etc, and would be completely incomprehensible to the vast majority of people in the USA or England). On the other hand, many people define the concept of a 'correct English word' as 'any word with a definition in the OED or Merriam Webster (ignoring proper nouns)', and leave other words as being 'wrong/foreign language'.
Either way, this is all moot when discussing a crossword puzzle contest, which explicitly limits itself to words in a specific dictionary + proper nouns. The problem of proper nouns is still extreme, and brings down the whole idea, but at least the problem of recognizing 'all possible common nouns that could be present in the crossword contest' is simple.
Either way, this is all moot when discussing a crossword puzzle contest, which explicitly limits itself to words in a specific dictionary + proper nouns. The problem of proper nouns is still extreme, and brings down the whole idea, but at least the problem of recognizing 'all possible common nouns that could be present in the crossword contest' is simple.