rotamer

https://doi.org/10.1351/goldbook.R05407
One of a set of conformers arising from restricted rotation about one single bond.
Source:
PAC, 1996, 68, 2193. 'Basic terminology of stereochemistry (IUPAC Recommendations 1996)' on page 2217 (https://doi.org/10.1351/pac199668122193)