What comes after length, area and volume? 
The length of the unit is 1.
  The area of the unit square is 1.
  The volume of the unit cube is 1.
  The $\color{red}{???}$ of the unit tesseract is 1.
  The $\color{blue}{???}$ of the unit 5-cube is 1.

So this is a fill in the blanks-question, but I've been wondering if there's a common term for this? I'd imagine it'd be "n-volume", but I cannot seem to find any uses of that term, so I'm guessing there is another term?

The term "hypervolume" is in use, but that doesn't tell you the dimension. I don't see any trouble using "$4$-volume" to describe the amount of space the unit tesseract occupies.
