Stereochemical feature of an electrocyclic reaction in which the substituents at the interacting termini of the conjugated system rotate in the same sense (both clockwise or both counterclockwise).
Source:
PAC, 2022, 94, 353. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)' on page 391 (https://doi.org/10.1515/pac-2018-1010)