interstice

noun

1. 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.
2. (figuratively)A fragment of space.

   “Relics of the British empire now mostly survive in the interstices of the global economy. They are the major winners from the fiscal haemorrhage that has resulted from financial globalisation.”

3. An interval of time required by the Roman Catholic Church between the attainment of different degrees of an order.
4. (broadly)A small interval of time free to be spent on activities other than one's primary goal.