Methylene
Pronunciation : Meth"yl*ene
Part of Speech : n.
Etymology : [F. m?thyl?ne, from Gr. wood spirit.] (Chem.)
Definition : Defn: A hydrocarbon radical, CH2, not known in the free state, but regarded as an essential residue and component of certain derivatives of methane; as, methylene bromide, CH2Br2; -- formerly called also methene. Methylene blue (Chem.), an artificial dyestuff consisting of a complex sulphur derivative of diphenyl amine; -- called also pure blue.
Source : Webster's Unabridged Dictionary, 1913