A heavy object attached to a rope or chain and used to moor a vessel to the sea bottom, typically one having a metal shank with a ring at one end for the rope and a pair of curved and/or barbed flukes at the other.

the boat, no longer held fast by its anchor, swung wildly

transitive verb

Moor (a ship) to the sea bottom with an anchor.

the ship was anchored in the lee of the island

moor,berth,harbour,be at anchor,tie up