1. That which intervenes between one thing and another; especially, a space between things closely set, or between the parts which compose a body; a narrow chink; a crack; a crevice; a hole; an interval; as, the interstices of a wall.
2. An interval of time; specifically, in the plural, the intervals which the canon law requires between the reception of the various degrees of orders. Nonobservance of the interstices . . . Is a sin. (Addis & Arnold)