What is the root word of extemporaneous?

The root word of "extemporaneous" is "tempor". It comes from the Latin word "tempus", which means "time".

Here's how it breaks down:

* "Ex" - meaning "out of" or "from"

* "Tempor" - meaning "time"

* "Aneous" - a suffix that indicates something related to or characterized by something

Therefore, "extemporaneous" literally means "out of time" or "not planned in advance".