# methylene

> English word · Noun · IPA /ˈmɛθɪliːn/ · frequency rank #62,318

## Definitions
1. The divalent group –CH₂– in which the free valencies are part of single bonds.
2. The same group, present as a repeating unit, in aliphatic compounds with names such as hexamethylenediamine.
3. The unstable carbene :CH₂

## Etymology
French méthylène, from Ancient Greek μέθυ (méthu, “wine”) + ὕλη (húlē, “wood”). By surface analysis, meth- + -ylene.

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/word/methylene