Polyatomic, a term that describes a molecule containing two or more atoms, can be expressed through different synonyms. These words include "multi-atomic," which refers to a molecule with multiple atoms, "complex," which describes a group of atoms holding together through chemical bonding, and "compound," which signifies a substance composed of two or more molecules. Additionally, "molecular," which denotes a structure that consists of two or more atoms held together by covalent bonds, can be used interchangeably with polyatomic. "Ion," a charged atom or molecule resulting from the gain or loss of electrons, is also a synonym of polyatomic, as some polyatomic molecules carry an electric charge.