The phrase "broad arc" generally refers to a wide or sweeping curve or trajectory that covers a large area. It suggests that something is not narrow or specific, but spans over a wide range or scope. Full definition
This work describes a very broad arc of inquiry, beginning with field work, followed by laboratory investigations, culminating in more field work. (news.brown.edu)
While the storyline covers the same broad arc as Victory, Re; Birth3 introduces a number of additions throughout its chapter - driven journey. (tech-gaming.com)
They form spirals, connected by broader arcs that stain more freely, without the sharp edges of a knife. (haberarts.com)