Groundbreaking means doing something nobody had done before. A groundbreaking study, groundbreaking work, truly groundbreaking.
It is heavy praise and heavily overused, particularly in press releases, where about nine things a week are groundbreaking. Genuinely groundbreaking work is usually recognised late. The literal sense is the ceremonial first digging at a building site: a groundbreaking ceremony, which is chiefly American. Note break new ground, which is the verb phrase behind it and is used more sparingly.
1adjectivegroundbreakingDoing something nobody had done before.
“The film was groundbreaking for its use of computer-generated dinosaurs.”
synonyms: pioneering, innovative
groundbreaking is a quality of pioneering.
From ground + breaking, in reference to the practice of breaking ground at the beginning of a new building or construction.
Etymology from Wiktionary, CC BY-SA