the initial substance of the universe from which all matter is said to be derived.
Origin of ylem
1948; adoption, in modern astrophysics, of Middle English ylem (Gower) < Medieval Latin (h)ȳlem, accusative of hȳlē < Greek hȳ́lē matter, wood
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
the original matter from which the basic elements are said to have been formed following the explosion postulated in the big bang theory of cosmology
Word Origin for ylem
Middle English, from Old French ilem, from Latin hӯlē stuff, matter, from Greek hulē wood, matter
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012