ultravacuum

== English == === Etymology === From ultra- +‎ vacuum. === Noun === ultravacuum (plural ultravacuums or ultravacua) A nearly perfect vacuum; i.e. an almost or fully complete absence of matter, especially a gas at very low pressure. === References === “ultravacuum”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022. “ultravacuum”, in TheFreeDictionary.com, Huntingdon Valley, Pa.: Farlex, Inc., 2003–2026