The term that describes large molecules that contain carbon and are held together by covalent bonds is organic molecules.

Here's why:

* Carbon's Bonding Ability: Carbon has the unique ability to form four covalent bonds, allowing it to create long chains, branched structures, and rings, which are the foundation of complex organic molecules.

* Covalent Bonds: Covalent bonds are strong bonds where atoms share electrons. This sharing allows carbon to form stable and diverse structures.

* Large Size: Organic molecules can be quite large, with many atoms linked together.

Let me know if you'd like more details on the types of organic molecules!