Wiktionary
gacyclidine
n. A psychoactive drug derived from tenocyclidine.
Wikipedia
Gacyclidine
Gacyclidine (GK-11) is a psychoactive drug which acts as a dissociative via functioning as a non-competitive NMDA receptor antagonist. It is closely related to phencyclidine (PCP), and specifically, is a derivative of tenocyclidine (TCP).