UNIQUE WORDS game to increase our vocabulary - alphabetical order

Vacillating:  Indecisive and wavering

Xenobiotics : 

Xenobiotic comes from the Greek words "xenos" (foreign) and "bios" (life). Essentially, it refers to anything that's not supposed to be there. 

Xenobiotic refers to chemical substances foreign to a living organism and not naturally produced or expected to be present within it. They can be synthetic compounds like drugs, industrial chemicals, pesticides, or even naturally occurring substances present at unusually high concentrations. 

Zoetrope:   a mechanical device consisting of a rotating drum ringed with narrow apertures through which an animated image is viewed.

Cacology literally means “evil-speaking,” and is used to refer to a poor choice of words or noticeably bad language

Eureka comes from the Ancient Greek word εὕρηκα heúrēka, meaning "I have found (it) 

Gastroenterology : study of stomach; intestines

Jelangkung is an Indonesian folk ritual of communicating with spirits of the dead.