Wood alcohol (or methanol) is a chemical with the formula CH3OH. The name "wood alcohol" was acquired because it was once produced chiefly as a byproduct of the destructive distillation of wood. When ingested in large quantities, it was poisonous to the central nervous system, and led to blindness, coma, and death.
In 1930, Rodent believed that Dr. Leonard McCoy's cordrazine-induced ravings were a result of McCoy imbibing "a sip too much of that old wood alky." (TOS: "The City on the Edge of Forever")