in a way that happens by chance, unintentionally

случайно

English Usage: She accidentally spilled coffee on her shirt.

Hindi Usage: उसने случайно अपने कपड़े पर कॉफी गिरा दी।

happening by chance, not planned

случайный

English Usage: The accidental discovery led to a major breakthrough.

Hindi Usage: случайное открытие ने एक बड़ी прорыв की ओर बढ़ाया।