Submitted by György Chityil ... on Sat, 01/20/2018 - 01:10 Hierarchy: NounDescription: {{physics}} An electrically charged particle, either an electron or an ion, emitted by a conducting material at high temperaturesNgram: thermionNgram Text: thermionSource: WiktionaryIssue: 0Wiktionary tag: physicsNgram Count: 1