Classical cannabinoids are natural or synthetic AB-bi/ABC-tri/-cyclics incorporating a resorcinol or benzopyran core moiety. They can be simply described as structural analogs of THC and CBD.
"Substances like THC, CBD, CBN, THCV, Delta-8-THC, HHC, H4CBD, THCP, HHCP, HU-210, HU-243, AM-905, AM-087, AM-411, belong to the classical cannabinoid structural class."
"Classical cannabinoids aren't like the cannabinoids that went into spice/k2 smoke blends which belong to a completely different structural class."
"JWH-091 (D8-THCP) belongs to the classical cannabinoid structural class but JWH-018 belongs to the alkyl-naphthoylindole structural class, despite both being cannabinoid agonists, and the JWH nickname, they are structurally unrelated to eachother."
"Classical cannabinoids were the first structural class of cannabinoids to ever be discovered."