Submitted by György Chityil ... on Fri, 01/19/2018 - 18:05 Hierarchy: InitialismPersonSingularDescription: '''F'''irst '''N'''ame '''U'''nknown (used as a given name on birth certificates when the first name is unknown)Ngram: FNUNgram Text: FNUSource: WiktionaryIssue: 0Ngram Count: 1