Preanimate matter was the building blocks of organic life. It was not truly alive, but displayed potential.

While scanning Ceti Alpha V in conjunction with Project Genesis, the USS Reliant detected a minor energy flux reading on one of the ship's dynoscanners, leading the crew to believe that the scanner was out of adjustment, that it contained life or that a particle of preanimate matter was caught in the matrix. (Star Trek II: The Wrath of Khan)