any of the more or less continuous military expeditions in the 11th to 13th centuries when Christian powers of Europe tried to recapture the Holy Land from the Muslims
go on a crusade; fight a holy war
exert oneself continuously, vigorously, or obtrusively to gain an end or engage in a crusade for a certain cause or person; be an advocate for; "The liberal party pushed for reforms"; "She is crusading for women's rights"; "The Dean is pushing for his favorite candidate"
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"; "the walls were covered with pictures"
a masonry fence (as around an estate or garden); "the wall followed the road"; "he ducked behind the garden wall and waited"
a layer of material that encloses space; "the walls of the cylinder were perforated"; "the container's walls were blue"
(anatomy) a layer (a lining or membrane) that encloses a structure; "stomach walls"
anything that suggests a wall in structure or function or effect; "a wall of water"; "a wall of smoke"; "a wall of prejudice"; "negotiations ran into a brick wall"
a vertical (or almost vertical) smooth rock face (as of a cave or mountain)
a difficult or awkward situation; "his back was to the wall"; "competition was pushing them to the wall"