Can a network covalent solid be amorphous? All the definitions I'm seeing give examples of crystalline solids like diamond or boron nitride. But I'm wondering if it also includes amorphous macromolecules like vulcanized rubber. I'm thinking "network" probably == "ordered array" but not sure if that's correct.
The most obvious example is amorphous carbon. As mentioned in a comment, another good example is glass (although, whether it's truly "solid" past the glass transition temperature). 

Really, a "network" simply means "solid with covalent bonding" and of course it's easy to imagine many possible amorphous network solids.

Vulcanized rubber might qualify too, but it would depend on whether there were many non-interlinked macromolecules. Usually macromolecules would be considered molecular solids due to the high number of non-bonded packing interactions. If the amount of cross-linking is high, classifying as a network solid makes sense.