Sex The classification of people as male or female. At birth, infants are assigned a sex based on a combination of bodily characteristics including: chromosomes, hormones, internal reproductive organs, and genitals.
Gender The socially constructed roles, behaviour, activities and attributes that a particular society considers appropriate for men and women.
Gender Identity One’s internal, personal sense of being a man or a woman (or a boy or a girl). For transgender people, their birth-assigned sex and their own internal sense of gender identity do not match.
Gender Expression External manifestation of one’s gender identity, usually expressed through “masculine,” “feminine” or gender-variant behavior, clothing, haircut, voice or body characteristics. Typically, transgender people seek to make their gender expression match their gender identity, rather than their birth-assigned sex.
Sexual Orientation Describes an individual’s enduring physical, romantic and/or emotional attraction to another person. Gender identity and sexual orientation are not the same. Transgender people may be straight, lesbian, gay or bisexual. For example, a man who transitions from male to female and is attracted to other women would be identified as a lesbian or a gay woman.
Asexual In science, it is an organism that reproduces without sexual activity with another organism. More broadly, asexual has come to mean being devoid of sexuality, often including not being sexually attracted to others, not desiring sexual interactions with others and/or not having sex.
Gender-variant/Gender non-conforming A broad term that refers to people whose gender does not fit with social or cultural expectations of their sex as it was assigned at birth. Gender variance doesn’t necessarily mean that an individual wants to change some aspect of their body or how they look, sound, or move through the world. It is used to identify and acknowledge that some people’s presentation doesn’t fit what others expect. Genderqueer is an umbrella term that some people use to describe a gender identity that doesn’t fit in the binary of male and female identities. Some people who don’t identify as entirely male or female use this term.
Transgender An umbrella term (adj.) for people whose gender identity and/or gender expression differs from the sex they were assigned at birth. The term may include but is not limited to: transsexuals, cross-dressers and other gender-variant people. Transgender people may identify as female-to-male (FTM) or male-to-female (MTF). Use the descriptive term (transgender, transsexual, cross-dresser, FTM or MTF) preferred by the individual. Transgender people may or may not decide to alter their bodies hormonally and/or surgically.
Cisgender People whose gender identity matches how they were identified at birth. If you were born and they called you a boy, and you are now an adult and you identify as a man, then your gender identity might be referred to as cisgender.
Transsexual (also Transexual) An older term which originated in the medical and psychological communities. While some transsexual people still prefer to use the term to describe themselves, many transgender people prefer the term transgender to transsexual. Unlike transgender, transsexual is not an umbrella term, as many transgender people do not identify as transsexual. It is best to ask which term an individual prefers.
Transvestite Derogatory see Cross-Dressing
Transition Altering one’s birth sex is not a one-step process; it is a complex process that occurs over a long period of time. Transition includes some or all of the following personal, legal and medical adjustments: telling one’s family, friends and/or co-workers; changing one’s name and/or sex on legal documents; hormone therapy; and possibly (though not always) one or more forms of surgery.
Sex Reassignment Surgery (SRS) Refers to surgical alteration, and is only one small part of transition (see Transition above). Preferred term to “sex change operation.” Not all transgender people choose to or can afford to have SRS. Journalists should avoid overemphasizing the role of SRS in the transition process.
Cross-Dressing To occasionally wear clothes traditionally associated with people of the other sex. Cross-dressers are usually comfortable with the sex they were assigned at birth and do not wish to change it. “Cross-dresser” should NOT be used to describe someone who has transitioned to live full-time as the other sex or who intends to do so in the future. Cross-dressing is a form of gender expression and is not necessarily tied to erotic activity. Cross-dressing is not indicative of sexual orientation.
Gender Identity Disorder (GID) A controversial DSM-IV diagnosis given to transgender and other gender- variant people. Because it labels people as “disordered,” Gender Identity Disorder is often considered offensive. The diagnosis is frequently given to children who don’t conform to expected gender norms in terms of dress, play or behavior. Such children are often subjected to intense psychotherapy, behavior modification and/or institutionalization. Replaces the outdated term “gender dysphoria.”
Intersex Describing a person whose biological sex is ambiguous. There are many genetic, hormonal or anatomical variations that make a person’s sex ambiguous (e.g., Klinefelter Syndrome). Parents and medical professionals usually assign intersex infants a sex and perform surgical operations to conform the infant’s body to that assignment. This practice has become increasingly controversial as intersex adults speak out against the practice. The term intersex is not interchangeable with or a synonym for transgender.
Biphobia Fear of bisexuals, often based on stereotypes, including inaccurate associations with infidelity, promiscuity and transmission of sexually transmitted diseases.
Bisexual, Bi An individual who is physically, romantically and/or emotionally attracted to men and women. Bisexuals need not have had sexual experience with both men and women; in fact, they need not have had any sexual experience at all to identify as bisexual.
Closeted Describes a person who is not open about his or her sexual orientation.
Coming Out A lifelong process of self-acceptance. People forge a lesbian, gay, bisexual or transgender identity first to themselves and then may reveal it to others. Publicly identifying one’s orientation may or may not be part of coming out.
Gay The adjective used to describe people whose enduring physical, romantic and/or emotional attractions are to people of the same sex (e.g., gay man, gay people). In contemporary contexts, lesbian (n. or adj.) is often a preferred term for women. Avoid identifying gay people as “homosexuals” an outdated term considered derogatory and offensive to many lesbian and gay people.
Heterosexual An adjective used to describe people whose enduring physical, romantic and/or emotional attraction is to people of the opposite sex. Also straight.
Homosexual Outdated clinical term considered derogatory and offensive by many gay and lesbian people. The Associated Press, New York Times and Washington Post restrict usage of the term. Gay and/or lesbian accurately describe those who are attracted to people of the same sex.
Homophobia Fear of lesbians and gay men. Prejudice is usually a more accurate description of hatred or antipathy toward LGBT people.
Lesbian A woman whose enduring physical, romantic and/or emotional attraction is to other women. Some lesbians may prefer to identify as gay (adj.) or as gay women.
LGBT / GLBT Acronym for “lesbian, gay, bisexual and transgender.” LGBT and/or GLBT are often used because they are more inclusive of the diversity of the community. Care should be taken to ensure that audiences are not confused by their use.
Lifestyle Inaccurate term used by anti-gay extremists to denigrate lesbian, gay, bisexual and transgender lives. As there is no one straight lifestyle, there is no one lesbian, gay, bisexual or transgender lifestyle.
Openly Gay Describes people who self-identify as lesbian or gay in their personal, public and/or professional lives. Also openly lesbian, openly bisexual, openly transgender.
Outing The act of publicly declaring (sometimes based on rumor and/or speculation) or revealing another person’s sexual orientation or gender identity without that person’s consent. Considered inappropriate by a large portion of the LGBT community.
Queer Traditionally a pejorative term, queer has been appropriated by some LGBT people to describe themselves. However, it is not universally accepted even within the LGBT community and should be avoided unless quoting or describing someone who self-identifies that way.
Sexual Orientation The scientifically accurate term for an individual’s enduring physical, romantic and/or emotional attraction to members of the same and/or opposite sex, including lesbian, gay, bisexual and heterosexual (straight) orientations.
* Definitions were taken from a variety of sources. I’ve poached a bunch from www.glaad.org which has a reference guide for journalists to support them in using appropriate terminology. Pejorative or inaccurate definitions are from GLAAD and are provided to help create an inclusive and responsive lexicon. Cory Silverberg’s terms from www.about.com are always thoughtfully contructed so I’ve added them where I can.