A full beard consists of hair on the chin, the cheeks, and the sideburns, without any natural or shaven gap.
In real life a full beard also includes a Mustache, but that's not true for a lot of bearded anime characters.
If the character has a mustache, you can tag it as:
A full beard can also be a Thick Beard, or thin Beard Stubble.
Visual comparison post #6608064