the.com/terrarium

means A sealed or open glass container where plants (and sometimes small animals) grow in a controlled miniature ecosystem.

from Built from Latin terra, 'earth,' plus the suffix -arium, 'a place for,' the same pattern that gave us aquarium (a place for water). The word rose alongside the Wardian case, a sealed glass box invented in the 1800s to smuggle live plants across oceans without them dying of salt air — accidentally proving that a tiny closed world could water itself forever through condensation, which is exactly the trick your terrarium is still performing on your shelf.