Green’s Dictionary of Slang

1. to expose someone as a homosexual against their will.

1990		Time 29 Jan. 67/1–2: The consensus is fast breaking down with the spread of the phenomenon known as ‘outing,’ the intentional exposure of secret gays by other gays.
1991		D. Jarman letter 1 July Smiling in Slow Motion (2000) 28: The Labour MPs should be outed first.
1998		I. Welsh Filth 203: Aye Inglis, ah’ll have you outed you cunt.
1999		Guardian G2 24 June 1: How I outed Rock Hudson.
2006		LeVay & Valente Human Sexuality 475: From time to time, politicians, preachers, and others who promote a strongly anti- gay agenda are themselves outed as homosexual.
2021		J. Ellroy Widespread Panic 3: Gay gauchos [...] scold me for outing them back in the homo-hate ’50s.

2. to reveal negative or personal information about an individual, group or organization.

1999		Indep. Rev. 18 June 16: He has recently been ‘outed’ in the tabloids for living with a woman and fathering a child.
2000		Guardian Guide 5–11 Feb. 8: Most hardmen of rap are still ambivalent about being openly outed as Christians.
2012		Independent (London) 19 Oct. 18/4: Other users of the forum began to be ‘outed’ in their turn.
2018		C. Hammer Scrublands [ebook] ‘My superiors are already pissed off at my presence being so spectacularly outed by you on national television’.