* No central database: There's no global database tracking every word spoken across the world.
* Subjectivity of "least spoken": What constitutes a "word" is subjective. Does it include slang, technical terms, or regional dialects?
* Constant change: Language is dynamic, and word usage constantly shifts.
However, some possibilities might be:
* Rare technical terms: Words used only in specific fields or professions (e.g., "quaternary" in geology).
* Obsolete words: Words that were common in the past but are no longer used (e.g., "wimple").
* Newly invented words: Words that have recently been coined and haven't gained widespread use.
Ultimately, the "least spoken word" is a fun thought experiment rather than a measurable concept.