nexus, n. — Green’s Dictionary of Slang

nexus n.

also bromo, spectrum, 2CB

[one of a large number of psychoactive substances first isolated by the American libertarian pharmacologist Dr Alexander Shulgin (b.1925), including DOM, STP, DOB, DOI and MDMA]

(drugs) 2C–B, a hallucinogen similar to LSD but without some of its more extreme side effects; most potent when used in conjunction with MDMA.

1987		J. Stevens Storming Heaven (1988) 359: LSD [...] has been superseded by a new generation of psychedelics with names like Ecstasy, Adam, Intellex, 2CB, Vitamin K and a handful of others.
1999		Indep. 28 June 6: Another drug, 2CB, also known as nexus, spectrum or bromo, is related to ecstasy and is becoming increasingly popular at festivals.
2004		Microgram Bulletin XXXVII:1 16: The drug, 4-bromo-2, 5-dimethoxyphenethylamine (2C-B), known as ‘Nexus,’ has recently been identified in the Seattle FD.