to use or abuse a hallucinogenic
drug of the deliriant variety.
The term is used most predominantly by those who frequent 420chan's deliriant board when referring to ingesting massive amounts of diphenhydramine (Benadryl in the
US).
Delving is notoriously unpleasant and often terrifying to the user. Yet some
drug users are drawn to delving by the very realistic looking hallucinations of non-existant people and objects, that are not
seen on other types of drugs.