CH20n

paraformaldehyde par`a*form*al"de*hyde, n. [Pref. para- + formaldehyde.] (Chem.) A polymer of formaldehyde obtained as a white crystalline substance by concentration of a formaldehyde solution. Formula {(CH20)n}. It dissolves in hot water with the release of formaldehyde, and is used as a disinfectant. [1913 Webster +PJC]