A chemical compound refers to a substance that is made up of two or more elements bonded together. In the context of this question, it is referring to a specific substance found in chocolate.
Related terms
Molecule: A molecule is the smallest unit of a chemical compound that retains its chemical properties.
Element: An element is a pure substance consisting of only one type of atom.
Bonding: Bonding refers to the connection between atoms in order to form compounds.