earthwork

n (formerly) large man-made bank of earth used as a fortification （旧时）土垒（用泥土筑成的大型防御工事）: the remains of ancient earthworks 古代土垒的残骸.

earnest, earnestly, earnestness, earning, earnings, earnings-related, earphone, earplug, earring, earrings, earshot, earsplitting, earth, earth science, earthen, earthenware, earthiness, earthlight, earthly, earthquake, earthworm, earthy, earwig, ease, eased, easel, easement, easier, easily, easiness, east, East-Ender, eastbound, Easter, Easter egg, Easter Sunday, easterly, eastern, easternmost, eastward,