* No Universal Database: There's no single, comprehensive dictionary that lists every word in every language.
* Constantly Changing: Languages are constantly evolving, with new words being created and old ones falling out of use.
* Defining "Word" is Hard: What constitutes a word can be subjective. Do we count slang, technical terms, regional dialects, or even proper nouns?
* Undocumented Languages: There are many languages, especially spoken by smaller communities, that haven't been fully documented or studied.
Estimates and Approximations:
* Oxford English Dictionary: The Oxford English Dictionary, a major English dictionary, contains over 600,000 words.
* Other Large Dictionaries: Other languages have dictionaries with hundreds of thousands of words.
* Total Number of Languages: Estimates of the total number of languages spoken worldwide range from around 6,000 to 7,000.
Conclusion:
While we can't give you a specific number, it's safe to say that the number of words in all the world's languages is incredibly vast and constantly changing.