(astronomy, cosmology, physics, now chiefly historical) In the Big Bang theory, the hot and dense plasma which made up the cosmos at the time of recombination in an early stage of its expansion and cooling, when the first atoms formed and photons decoupled. The ylem is regarded as the source of the cosmic microwave background.

(organic chemistry) used to form the names of bivalent radicals

past participle of learn

past participle of leave

Obsolete spelling of island

plural of ylelond