The moiety, —CH2—.
* * *
meth·y·lene 'meth-ə-.lēn, -lən n a bivalent hydrocarbon radical CH2 derived from methane by removal of two hydrogen atoms
* * *
meth·y·lene (methґə-lēn) the bivalent hydrocarbon radical CH2 or CH2. Called also methene.Medical dictionary. 2011.