Definition of "Wall" :

noun: an embankment built around a space for defensive purposes

"They blew the trumpet and the walls came tumbling down."

noun: an architectural partition with a height and length greater than its thickness; used to divide or enclose an area or to support another structure

"The south wall had a small window."

noun: a masonry fence (as around an estate or garden)

"The wall followed the road."

noun: a layer of material that encloses space

"The walls of the cylinder were perforated."

noun: (anatomy) a layer (a lining or membrane) that encloses a structure

"Stomach walls."

noun: anything that suggests a wall in structure or function or effect

"A wall of water."

noun: a vertical (or almost vertical) smooth rock face (as of a cave or mountain)

noun: a difficult or awkward situation

"His back was to the wall."

verb: surround with a wall in order to fortify