Over two millenia ago, ancient Chinese civilizations began to create artistic miniature landscapes. About seven hundred years ago, that practice was adopted by Japanese Zen Buddhists, who turned it into a spiritual activity. Eventually, they stopped doing whole landscapes and made the activity centered around miniature trees, which they called bonsai, a noun roughly meaning "tray plant" (these trees were often grown in trays). The roots of that hopefully-familiar term are bon, meaning "pot", "bowl", or "tray", and sai, a verb meaning "to plant". Similar to the practice's evolution, those words came from China, apparently from characters meaning "tub" and "cultivation"; not much is known after that. Google NGrams shows high usage of the word in the 1960s and 1990s but large dips of unpopularity in the '40s and '70s.
Hello! I'm Adam Aleksic, a sophomore studying government and linguistics at Harvard University, where I co-founded the Harvard Undergraduate Linguistics Society. In addition to etymology, I also really enjoy politics, vexillology, geography, board games, conlanging, and law.