(mathematics) A stochastic path consisting of a series of sequential movements, the direction (and sometime length) of which is chosen at random

(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.

Short for Great Wall of China. / (astronomy) Either of two identified areas containing hundreds of galaxies.

(US) A raised platform on the roof of a house, especially one on a coastal house originally used for viewing the arrival of shipping

(Britain) A retail store floor supervisor.

Either of two species of fern in the genus Asplenium (Asplenium rhizophyllum or Asplenium sibiricum) that produce new plantlets from the tips of their leaves.

present participle of walk on eggshells

(idiomatic, US) To perform actions consistent with one's claims.

(idiomatic) To be overly careful in dealing with a person or situation because they get angry or offended very easily; to try very hard not to upset someone or something.