The spatial arrangement of the atoms affording distinction between stereoisomers which can be interconverted by rotations about formally single bonds. Some authorities extend the term to include inversion at trigonal pyramidal centres and other polytopal rearrangements.
See also: conformer, bisecting conformation, chair, boat, twist, crown conformation, envelope conformation, half-chair, staggered conformation, tub conformation
Sources:
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1099 (https://doi.org/10.1351/pac199466051077)
PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2204 (https://doi.org/10.1351/pac199668122193)