n. One of the holes in a dove-cote or pigeon-house through which the birds pass in and out.n. Hence A little compartment or division in a case for papers, a bureau, a desk, or the like.n. One of a series of holes in an arch of a furnace through which the gases of combustion pass.n. One of a series of holes in the block at the bottom of a keir through which its liquid contents can be discharged.n. plural An old English game, resembling modern bagatelle, in which balls were rolled through little cavities or arches.n. In printing, an over-wide space between printed words. Also called rat-hole.To place or file away in a pigeonhole; hence, to lay aside for future consideration; hence, to lay aside and ignore or forget; “shelve”; treat with intentional neglect: as, to pigeonhole an application for an appointment; to pigeonhole a scheme.