Wiktionary
n. A supposed polymeric form of water reported to have been produced in fine capillaries; now known to be illusory
Wikipedia
Polywater was a hypothesized polymerized form of water that was the subject of much scientific controversy during the late 1960s. By 1969 the popular press had taken notice and sparked fears of a "polywater gap" in the USA.
Increased press attention also brought with it increased scientific attention, and as early as 1970 doubts about its authenticity were being circulated. By 1973 it was found to be illusory, being just water with any number of common organic compounds contaminating it.
Today, polywater is best known as an example of pathological science.
Usage examples of "polywater".
Rogo and I had worked up a game involving our polywater bed, which he loved bouncing around on, especially when it was rolling like surf.
Even warm enough, in places, that the polywater turned into its gaseous state, carrying the ancient bacteria aloft on trade winds, into the Jet Stream, and over land -- where it found its way to landlocked lakes, rivers, reservoirs.
Fortunately, the human body manufactures antibodies which kill the bacteria and reverts the polywater to normal, though not without side effects -- chills, fever, memory loss.
I got out a novelette about polywater just before it became apparent that this seemingly intriguing substance was a practical joke that eager and careless physical chemists had played on themselves.