Available Definitions:
1) superl. - Not deep; having little depth; shoal.
2) superl. - Not deep in tone.
3) superl. - Not intellectually deep; not profound; not penetrating deeply; simple; not wise or knowing; ignorant; superficial; as, a shallow mind; shallow learning.
4) n. - A place in a body of water where the water is not deep; a shoal; a flat; a shelf.
5) n. - The rudd.
6) v. t. - To make shallow.
7) v. i. - To become shallow, as water.