molecular similarity

https://doi.org/10.1351/goldbook.11475

The degree to which two molecules resemble one another as calculated from their respective 2D or 3D properties, molecular fingerprints, fragment keys, or superimposed 3D structures that usually ranges from 1 (identical) to 0 (dissimilar).

Note: Tanimoto or Tversky similarities for 2D structures and Carbo or Hodgkin for 3D structures.
Source:
PAC, 2016, 88, 239. 'Glossary of terms used in computational drug design, part II (IUPAC Recommendations 2015)' on page 250 (https://doi.org/10.1515/pac-2012-1204)