https://doi.org/10.1351/goldbook.A00479
The traditional name (van 't Hoff) for a carbon atom that is attached to four different entities (atoms or groups), e.g. Cabcd.
See also:
chirality centre
Sources:
Blue Book, p. 480 [Terms] [Book]
PAC, 1996, 68, 2193. (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2200 [Terms] [Paper]