IPA: //ˈɡraʊndˌbreɪkər//
KK: /ˈgraʊndˌbreɪkər/
A person or thing that introduces new ideas or methods, often leading to significant changes or advancements.
The scientist was a true groundbreaker in the field of renewable energy.
Groundbreaker is formed from "ground" (from Old English *grund*, meaning the surface of the earth) and "breaker" (from Old English *brecan*, meaning to break). The word describes someone or something that breaks new ground, often in a metaphorical sense, indicating innovation or pioneering efforts.
Think of someone who 'breaks' ('brecan') the 'ground' ('grund') to create something new — that's why a groundbreaker is someone who innovates or pioneers.
No commonly confused words.