全然

Etymology

Orthographic borrowing from Chinese 全然 (quánrán) in the early 1800s from 白話小説 (hakuwa shōsetsu, literally “white-speech novels”), a genre using more colloquial styles, initially with furigana indicating a reading of まったく (mattaku, “completely”).[1]
First cited to a text from 1823, with the ぜんぜん (zenzen) reading became more common starting from the late 1890s.[1]

woah didn’t realize it was quite a recent addition to the language :thinking_cirno: