Anchor

noun

1. A tool used to moor a vessel to the bottom of a sea or river to resist movement.
2. An iron device so shaped as to grip the bottom and hold a vessel at her berth by the chain or rope attached. (FM 55-501).
3. The combined anchoring gear (anchor, rode, bill/peak and fittings such as bitts, cat, and windlass.)
4. Representation of the nautical tool, used as a heraldic charge.
5. Any instrument serving a purpose like that of a ship's anchor, such as an arrangement of timber to hold a dam fast; a device to hold the end of a bridge cable etc.; or a device used in metalworking to hold the core of a mould in place.