Something that can be substituted for something else; a viable replacement.

(mathematics) A norm of an ordinary Euclidean space, for which the Pythagorean theorem holds, defined by |x|=√

A commune in the eastern suburbs of Paris, Île-de-France, France.

Of or relating to any member of the superfamily (Ceboidea) of monkeys, believed to have evolved from prosimians isolated in South America, and including the marmosets, capuchins, tamarins, sapajous...