Not deep; of little depth: as, a shallow brook; a shallow place; a shallow vessel or dish.Not deep intellectually; superficial: as, a shallow person; a shallow mind.n. A place where the water is not deep; a shoal; a shelf; a flat; a bank.To make shallow; decrease the depth of.To become shallow; decrease in depth: as, the water shallows rapidly as one approaches the bar.n. The rudd, a fish.