shallow, shoal -- (make shallow; "The silt shallowed the canal")
shallow, shoal -- (become shallow; "the lake shallowed over time")
Overview of adj shallow
The adj shallow has 3 senses
shallow -- (lacking physical depth; having little spatial extension downward or inward from an outer surface or backward or outward from a center; "shallow water"; "a shallow dish"; "a shallow cut"; "a shallow closet"; "established a shallow beachhead"; "hit the ball to shallow left field")
shallow -- (not deep or strong; not affecting one deeply; "shallow breathing"; "a night of shallow fretful sleep"; "in a shallow trance")
shallow -- (lacking depth of intellect or knowledge; concerned only with what is obvious; "shallow people"; "his arguments seemed shallow and tedious")