Heteroelement refers to an atom or an element that is distinct from the rest of the elements in a particular molecule. There are several other words that can be used to describe heteroelements, including alien elements, non-typical atoms, or non-homologous elements. These words are used to indicate the presence of any element that is different from the predominant element in a compound. Other synonyms for heteroelement include outsider elements, non-constitutive atoms, and unusual atomic entities. These synonyms are often used interchangeably depending on the context. In general, heteroelement refers to any element that exists outside the primary element in a molecule or compound.