Other forms: broke ground; breaking ground; breaks ground
To break ground is to begin a project. It often refers to starting a new building project, when politicians or business owners might use a ceremonial shovel to dig the first bit of dirt.
Break ground can be used literally, as in first hitting the dirt with shovels to dig up the ground so that a building's foundation can be laid. Or it can be used figuratively, to describe starting any major task or project. For example, you might break ground on your big science project by beginning your initial research. It's important to distinguish the phrase break ground from the phrase break new ground, which specifically implies doing something innovative that has never been done before.