-yl

hydrocarbon radical occurring in many compounds, 1835, from French méthylène (1834), coined by Jean-Baptiste-André Dumas (1800-1884) and Eugène-Melchior Péligot (1811-1890) from Greek methy "wine" (see mead (n.1)) + hylē "wood" (which is of uncertain etymology) + Greek name-forming element -ene. So called because it was detected in wood alcohol.

"The breakdown of methylene into methyl and -ene, and the identification of the last syllable of methyl with the general suffix -yl, led to the use of meth- as a separate combining-element, as, for example, in methane, methacrylic" [Flood]. The color methylene-blue (1880) was derived from dimethylanaline.

gaseous hydrocarbon, 1860, from French acétylène, coined by French chemist Pierre Eugène Marcellin Berthelot from chemical ending -ene + acetyl, which was coined from acetic + -yl in 1839 by German chemist Justus von Liebig. Liebig's coinage was in reference to a different radical; acetyl was transferred to its current sense in 1850s, but Berthelot's coinage was based on the original use of acetyl.