Closeted
The slang term "being in the closet" has been used to describe keeping secret one's sexual behaviors or orientation disapproved of by society; typically homosexuality, bisexuality, or transgenderism, but also including various paraphilias. (The term has also been used semiseriously to refer to other personal preferences; e.g. "John Doe is a closet postmodernist, communist, liberal, etc.")
A "closeted" person originally referred only to lesbians, gays and bisexuals who kept their relationship preferences secret. The reason is usually that the person does not want to face the environment's homophobia. In many places in the world, coming out of the closet means losing your job, home, family, friends, religious and political memberships. There is often also a real risk of being the victim of violent hate crime.
In later years it has, often jokingly, come to refer to any person who keeps certain preferences secret, e.g. closet biblioholist, closet cross-dresser.
Coming out of the closet describes voluntarily making public one's sexual behaviors or orientation, "being out" to not concealing one's sexual behaviors or orientation, and "outing" for making public the sexual behaviors or orientation of another who would prefer to keep this information secret.
Many people who identify themselves as homosexual, or who might prefer homosexual activities or relationships, have engaged in heterosexual activities or even have long-term heterosexual relationships. Such "heterosexual" behavior by people who would otherwise be homosexual has often been part of being "in the closet", and may be becoming less common as acceptance of homosexuality increases.
Coming out has an etiquette of its own, developed through the experiences of people who did it in a way they later decided was inappropriate and more stressful than it had to be: for instance, among other things, it's encouraged not to announce homosexuality in a fight or while drunk or delirious for any other reason; it is encouraged to leave the subject alone until the person it was announced to chooses to broach it again.
Coming out is often a gradual process. It is common to come out first to a trusted friend or family member, and wait to come out to others. Some people are "out" at work but not to their families, or vice-versa. A person might say "I'm out at work, but I'm not out to my family".
Not surprisingly, some studies have found that the degree to which a person can be "out" in a large number of life situations seems to strongly correlate with lack of stress and freedom from neurosis.
Today more homosexuals than ever are "out", and their general belief is that being in the closet is unhealthy for the individual. A common saying is, "Closets are for clothes". One major gay magazine is titled Out Magazine.
It is important to note that the term "coming out of the closet" about something has been so seemlessly integrated into the popular culture that it can, and often is, used to describe anything that was previously hidden but suddenly revealed. (Example: "John came out of the closet about his gambling addiction; "Janice came out of the closet when she told everyone she secretly loved chocolate.")
See LGB community, Famous gay lesbian or bisexual people, Homophobia
There is also a varient of this concept called "The Broom Closet" that refers to people who hide the fact that they are followers of the Wicca religion for fear of social rejection and reprisals.
Activists for Wicca and general religious freedom and tolerance stress that the same problem of the regular Closet concept also applies to the variant and encourage people to come out for the same reasons.
"Out" is also the name of an American gay and lesbian periodical.