- acetylThe univalent radical CH₃CO- derived from acetic acid.
- hylaA tree frog of the genus Hyla.
- hylA unit of mass that is accelerated at a rate of 1 meter per second squared (1 m/s²) by a force of 1 kilogram-force, equivalent to 9.80665 kilograms.
- hyleSynonym of matter, physical substance.
- hylo-matter
- hyloistSomeone who believes that matter is God, or that there is no distinction between the two; a materialist.
- mesohylThe gelatinous matrix within a sponge, filling the space between the external pinacoderm and the internal choanoderm.
- protyleA hypothetical base substance from which all chemical elements were believed to have been made; subatomic particles.
- pterylaOne of the areas of a bird's skin on which feathers grow.
- -ylA univalent radical or functional group formed from a given molecule. Thus propyl from propane, benzyl from benzene, and so forth.
- ylemIn the Big Bang theory, the hot and dense plasma that made up the matter in the cosmos following the initial baryogenesis at an early stage of its expansion and cooling, from which the first atoms formed and photons decoupled. The emission of photons in this phase is regarded as the source of the cosmic microwave background.
- YliasterPrime matter, consisting of body and soul.