Unknown.
But the issue isn't the font that Terminal is using in the actual term window.. it's the font it's attempting to use for the menubar, I believe. And that isn't changable, AFAIK.
EDIT: Untrue, I just tested and unfortunately, you cannot choose a different font from the prefs (at least I couldn't). The only way to fix it was to re-enable whatever font it was using that you disabled (default is Monaco). After that, you can change the font and disable what you want, provided you don't disable what it's using, or you have to go back through this rigamarole again.
(And by "prefs", I mean the Window Settings -> Display)