What is the meaning of root word pos?

The root word "pos" is not a recognized root word in the English language. It's possible you are thinking of a similar word or root, such as:

* "pos-" This is a prefix that means "after" or "behind." It comes from the Latin word "post," meaning "after."

* Examples: postpone (to put off until later), postmortem (occurring after death).

* "posit" This is a verb meaning "to put forward as a fact or proposition." It is not a root word itself, but is derived from the Latin word "ponere," meaning "to place" or "to put."

If you could provide more context or an example of where you encountered the word "pos," I might be able to give you a more accurate answer.