methylene

/M EH1 TH IH0 L IY0 N/
noun
  1. 1

    The divalent radical CH2< in which the free valencies are part of single bonds.

  2. 2

    The same group, present as a repeating unit, in aliphatic compounds with names such as hexamethylenediamine.

  3. 3

    The unstable carbene CH2:

Synonyms

Source: https://en.wiktionary.org/wiki/methylene