Speaking of "definitions"...
A Fuge or "refugium" is a "seperate" tank or chamber from the sump...drain in..drain out...and whatever your "growing" inside...
A "Sump" is where you place the return pump to push water back to the MT...
If you divide a small chamber in your "fuge" for the return pump, "that" is the sump...
If you make it large enough to house your skimmer as well thats fine..still refered to as a sump and is taking room from your "fuge" if you choose to place them both in the same tank...
Now your fuge area/volume is less and you'll need to re-do your calcs for flow...
And have created a "Sumpfugium"...