Aquarium
mid 19th century: from Latin, neuter of aquarius ‘of water’, on the pattern of vivarium .
wiktionary
Borrowed from Latin aquārium, neuter of aquārius(“of or pertaining to water”), from aqua + -arium. Doublet of ewer; see also Aquarius.
etymonline
aquarium (n.)
1830, noun use of neuter of Latin aquarius "pertaining to water," as a noun, "water-carrier," genitive of aqua "water" (from PIE root *akwa- "water"). The word existed in Latin, but there it meant "drinking place for cattle." Originally especially for an artificial pond growing aquatic plants; of indoor "ocean gardens" by 1853. The Victorian mania for indoor aquariums began with the book "The Aquarium," published 1854 by English naturalist Philip Henry Gosse. An earlier attempt at a name for "fish tank" was marine vivarium.