Submitted by György Chityil ... on Fri, 01/19/2018 - 23:58 Hierarchy: NounDescription: {{astronomy}} A rotating disk of dense gas surrounding a young newly formed star, and from which planets may be formed.Ngram: proplanetary diskNgram Text: proplanetary diskSource: WiktionaryIssue: 0Wiktionary tag: astronomyNgram Count: 2
