"Wide arches" refers to the horizontal curved shape that is usually made by someone's eyebrows when they lift them up to show surprise or shock. Full definition
On the visual side, car is packed with wider arches, front lip, grille, side skirts and rear wing. (ps-garage.com)
Start pulling a dumbbell from the floor over your head, taking them in wide arch. (fitnessandpower.com)
The main house has an open plan downstairs with the rooms connected by wide arches, along with the kitchen and living room there is a bathroom and a utility room on this level. (crusadertravel.com)