Of a part of the body: lacking a normal or functional orifice or an open channel; (of a person or animal) †having such a part (obsolete); = "imperforate".
Lacking a hole or holes; not pierced with a hole or holes.
Of a postage stamp: taken from a sheet in which the individual stamps are not separated by rows of perforations, and hence not having perforated edges; (of a sheet of stamps) lacking perforations.