The story
* out + -ness. ** (philosophy): Possibly coined by George Berkeley for his 1709 Essay Towards a New Theory of Vision ** (sexuality): Popularised by Lynne Pearlman in her 1989 thesis Theorizing Lesbian Oppression and the Politics of Outness in the Case of Waterman v. National Life Assurance.
Etymology from Wiktionary, CC BY-SA 4.0.