\R['e]`seau"\, n. [F.]
A network; specif.:
(a) (Astron.) A system of lines forming small squares of
    standard size, which is photographed, by a separate
    exposure, on the same plate with star images to
    facilitate measurements, detect changes of the film, etc.
(b) In lace, a ground or foundation of regular meshes, like
    network.