From Longman Dictionary of Contemporary Englishintersticein‧ter‧stice /ɪnˈtɜːstɪs $ -ɜːr-/ noun [countable usually plural] formal SPACE/GAPa small space or crack in something or between things
Examples from the Corpus
interstice• Small plants were growing in the interstices of the rock.Origin interstice (1400-1500) French Latin interstitus, past participle of intersistere “to stand still in the middle” 