I suppose one could use the term typeface or font for what I'm working on. Never gave much thought to it myself, but based on pspeed's link font might be a better fit.
"Open up Microsoft Word and you're asked to choose a font, not a typeface. From the perspective of Microsoft's designers, this makes perfect sense. At any given time, after all, you're working in a specific size and weight of a typeface. This is the proper term."
In this case the TrueTypeKey, the AssetKey for the font loader, is specific for each size and weight. You would have one key for bold 12 point serif, another for italic 12 point serif and another for plain 20 point serif so each instance of the font class represents a single font rather than an entire typeface.
This is based on java.awt.Font in which a different instance is required for each size and style.
P.S. Thanks for bringing it up actually, I actually didn't know the difference between typeface and font and it's good to know. I've learned a good deal about fonts recently heh. Creating an atlas isn't as cut and dry as I thought it would be. For instance, obviously, some characters extend below the baseline and java gives you a descent variable that's supposed to tell you how far, but according to the docs some characters extend below even that value and into the next line. Others might extend beyond their Xadvance into the next character etc...