無闇に
むやみに · muyamini · JLPT N1 · adverb
at random
🎲 無 = without + 闇 = darkness: acting blindly, with no light to reason by
It originally meant groping in the dark, with no light to guide you, so acting without reason. Today it means unreasonably or at random, as in 無闇に怒る: getting angry for no reason.