What does it literally means and where comes from A man a word word?

The phrase "A man, a word" is not a common English expression and doesn't have a specific meaning. It's possible that it's:

* A misremembered or misheard phrase: It could be a distorted version of another saying.

* An incomplete phrase: It might be part of a larger statement or quote.

* A phrase used in a specific context: Perhaps it's a saying within a particular culture or community.

If you could provide more context about where you heard this phrase, it would be easier to understand its meaning.

For example, did you see it in a book, movie, or hear it in conversation? Knowing the context will help me understand what the phrase means in that specific situation.