sand
built on sand: seebuilt.
bury your head in the sand: seebury.
(draw) a line in the sand: seeline.
rope of sand: seerope.
run into the sand come to nothing.
2006New York Review of Books What struck Jane Addams in retrospect … was that immediately after this lecture, everything ran into the sand.
the sands (of time) are running out the allotted time is nearly at an end.
☞ The image here is of the sand in an hourglass moving from the upper chamber to the lower.
shifting sands: seeshifting.