A sandbank or sandbar creating a shallow.
A shallow in a body of water.
A large number of fish (or other sea creatures) of the same species swimming together.
Any large number of persons or things.
To become shallow.
To arrive at a shallow (or less deep) area.
To collect in a shoal; to throng.
To cause a shallowing; to come to a more shallow part of.
A small indication of a larger possibility; the first part encountered of a problem that is much bigger than it seems.