Interstice

Interstice: A small space between things, especially between things that are usually closely spaced, such as cells. Interstices are the cracks and crevices, the breaks, the gaps.

The word "interstice" comes from the Latin "interstitium" which was derived from "inter" meaning "between" + "sistere" meaning "to stand" = to stand between.

Interstices can also refer to gaps in time and to special niches in a larger expanse.