What terms applies best to all material in this tissue that is not cellular?

Extracellular matrix

Explanation:

The term matrix applies to all extracellular material seen, including the base substance and all fibers.

Connective tissue (CT) is one of the four main modules of muscles. While it is the utmost abundant and widely distributed primary tissue, the amount of connective tissue in a particular organ varies. Like the wooden structure of a house, connective tissue provides structure and support throughout the body.