To separate with a wall. / (figuratively, by extension) To isolate completely.

(transitive) To seal with a wall.

(construction) A double wall of masonry connected by an air space.

(idiomatic) alternative form of writing on the wall

plural of wall clock

(physics) An interface separating magnetic domains. / (astrophysics) A two-dimensional singularity hypothesized in string theory.

(history) A wall that parted the city of Berlin until 1989, constructed by the German Democratic Republic to keep East Germans from escaping to West Berlin.

(politics) Any barrier designed to keep people from crossing a border, e.g. the one proposed to keep people from crossing from Mexico into the United States.

A restaurant, shop or other establishment catering to customers that is particularly inconspicuous and easily overlooked. / (colloquial, chiefly Britain) An automated teller machine (ATM).

(US, idiomatic, slang) With maximum effort or commitment.