interstices

plural of interstice

A small opening or space between objects, especially adjacent objects or objects set closely together, such as between cords in a rope, components of a multiconductor electrical cable or atoms in a crystal.
(figuratively) A fragment of space.
An interval of time required by the Roman Catholic Church between the attainment of different degrees of an order.
(broadly) A small interval of time free to be spent on activities other than one's primary goal.