groundbreaking; revolutionary; epoch-making
Describes something that marks a major turning point or opens a new era; often used for inventions, discoveries, or policies.
この発明は画期的だ。
This invention is groundbreaking.
画期的な治療法が開発された。
A revolutionary treatment has been developed.
This device is said to be a groundbreaking invention in the medical field.
The scientists announced that they had made a groundbreaking discovery.
This company developed a revolutionary technology that transformed the industry.
The signing of that treaty was an epoch-making event in history.
画期的 describes something groundbreaking or innovative regardless of historical timing, while 歴史的 (in its 'historic' sense) stresses lasting importance within the flow of history.
画期的 focuses on something being groundbreaking or epoch-making in nature, while 飛躍的 focuses on the scale and speed of improvement or growth.