Dictionary / Vocabulary / 画期的
かっきてき
ground-breaking; revolutionary; unprecedented; epoch-making
common word Also written 劃期的
当時としちゃ画期的な発明だったね。
It was a groundbreaking invention at the time.
これは、画期的な発明だから教科書に載るかもよ。
This invention is so revolutionary, it might make it into the textbooks.