ridiculously; unusually; exceptionally
Used adverbially to emphasize an extreme degree, often with a nuance of surprise or mild criticism. Can be used both positively and negatively.
It's ridiculously hot today, isn't it?
He runs unusually fast.
Standard kanji spelling for the adverbial form.
Katakana spelling used for emphasis or in informal contexts.
Adverbial form of 馬鹿 (fool, stupid). The origin of 馬鹿 is uncertain, but it is a common word in modern Japanese.