Office for Mac 2011 Font Tahoma working but not showing in font list
Solution 1:
Microsoft's applications use their own font cache. You could try deleting the cache and launch one of the applications again. It should just generate a new cache file.
You will find the cache file named "Office Font Cache" in "~/Library/Application Support/Microsoft/Office/Preferences/Office 2011".
Solution 2:
I placed a copy of tahoma.ttf from HD/Library/Fonts into HD/Library/Fonts/Microsoft and restarted Word. So it's a duplicate but it now shows in Word.