an intervening space.

a small or narrow space or interval between things or parts, esp. when one of a series of alternating uniform spaces and parts

the interstices between the slats of a fence.

Roman Catholic Church . the interval of time that must elapse, as required by canon law, before promotion to a higher degree of orders.

an interval of time.

noun

closing , closure

noun

aperture , chink , cleft , cranny , crevice , fissure , gap , hole , interval , slit , space , interspace , separation , areola , areole , crack , opening , orifice , pore