fȯrm+ noun
Etymology: International Scientific Vocabulary form- + aldehyde; originally formed as German formaldehyd
: a very reactive aldehyde HCHO that has a tendency to polymerize, that is a colorless pungent irritating combustible gas when pure but is conveniently handled in the form of aqueous solutions or solid polymers (as paraformaldehyde), that is usually made by oxidation of methanol or of gaseous hydrocarbons, and that is used chiefly as a disinfectant and preservative, as a hardening and insolubilizing agent especially for proteins, and in the synthesis of other compounds (as pentaerythritol) and of phenolic and other synthetic resins — called also formic aldehyde, methanal