IPA: /sɪsˈtɜrnəl/
KK: /sɪsˈtɜrnəl/
Relating to a cistern, which is a container for storing water or other liquids.
The building's design included a cisternal system for rainwater collection.
Cisternal → It is formed from "cisterna" (from Latin, meaning a reservoir or tank) and the suffix "-al" (meaning pertaining to). The word "cisternal" refers to something that pertains to or is related to a cistern or reservoir.
Think of a "cistern" as a reservoir, and remember that "cisternal" means related to that reservoir.