Walls

1. A rampart of earth, stones etc. built up for defensive purposes.
2. A structure built for defense surrounding a city, castle etc.

   The town wall was surrounded by a moat.

3. Each of the substantial structures acting either as the exterior of or divisions within a structure.

   We're adding another wall in this room during the remodeling.  The wind blew against the walls of the tent.

4. A point of desperation.
5. A point of defeat or extinction.
6. An impediment to free movement.

   A wall of police officers met the protesters before they reached the capitol steps.

7. A type of butterfly (Lasiommata megera).
8. (often in combination) A barrier.

   a seawall;  a firewall

9. A barrier to vision.
10. Something with the apparent solidity and dimensions of a building wall.

    a wall of sound;  a wall of water

11. A divisive or containing structure in an organ or cavity.
12. (auction) A fictional bidder used to increase the price at an auction.
13. A doctor who tries to admit as few patients as possible.
14. A line of defenders set up between an opposing free-kick taker and the goal.
15. A personal notice board listing messages of interest to a particular user.

1. To enclose with, or as if with, a wall or walls.

   He walled the study with books.

1. To boil.
2. To well, as water; spring.

noun

A spring of water.

noun

A kind of knot often used at the end of a rope; a wall knot or wale.

verb

To make a wall knot on the end of (a rope).