- Hiatus - Pit or cavity - A small opening; a small pit or depression; a small blank
space; a gap or vacancy; a hiatus. - A small opening; a small depression or cavity; a space, as
a vacant space between the cells of plants, or one of the spaces left
among the tissues of the lower animals, which serve in place of vessels
for the circulation of the body fluids, or the cavity or sac, usually
of very small size, in a mucous membrane.