Achiral, a term widely used in chemistry, refers to molecules that cannot be superimposed on their mirror images. However, there are numerous synonyms that can be used interchangeably to describe this characteristic. One such synonymous term is "asymmetric", which highlights the lack of symmetry within the molecule. Similarly, the word "non-superposable" denotes molecules that cannot align perfectly with their mirror images. Moreover, "chirally inactive" is another phrase that can be used to describe achiral compounds, emphasizing their inability to exhibit chirality. Overall, these synonyms help scientists and researchers better understand and classify molecules based on their symmetry properties and molecular behavior.