The language of gender and sexuality is a shifting, ever-evolving terrain marked by an appreciable degree of nuance and, on occasion, contestation (see, for example, Julia Serano's blog post, "Regarding Trans* and Transgenderism").
It's important to note that there is sometimes a lag in academic language--for example, in the health sciences (see the article, "An Exploration of Terminology Related to Sexuality and Gender")--compared to that used colloquially.
Heed subject headings in catalogs and databases that employ outdated terminology or assign inaccurate or incorrect terms (see, for example, the article, "Transcending Library Catalogs").
For a broader view on how gender is inscribed in language around the world and how modern language use is changing to incorporate nonbinary gender identities, see the interactive piece from Reuters called "Beyond pronouns: How languages are reshaping to include non-binary and gender-nonconforming people."
The classification of a person as male or female. At birth, infants are assigned a sex, usually based on the appearance of their external anatomy. (This is what is written on the birth certificate.) A person's sex, however, is actually a combination of bodily characteristics including: chromosomes, hormones, internal and external reproductive organs, and secondary sex characteristics.
A person's internal, deeply held sense of their gender. For transgender people, their own internal gender identity does not match the sex they were assigned at birth. Most people have a gender identity of man or woman (or boy or girl). For some people, their gender identity does not fit neatly into one of those two choices (see non-binary and/or genderqueer below.) Unlike gender expression (see below) gender identity is not visible to others.
External manifestations of gender, expressed through a person's name, pronouns, clothing, haircut, behavior, voice, and/or body characteristics. Society identifies these cues as masculine and feminine, although what is considered masculine or feminine changes over time and varies by culture. Typically, transgender people seek to align their gender expression with their gender identity, rather than the sex they were assigned at birth.
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.
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). Sometimes lesbian (n. or adj.) is the preferred term for women.
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.
A person who has the capacity to form enduring physical, romantic, and/ or emotional attractions to those of the same gender or to those of another gender. People may experience this attraction in differing ways and degrees over their lifetime.
An umbrella term for people whose gender identity and/or gender expression differs from what is typically associated with the sex they were assigned at birth. People under the transgender umbrella may describe themselves using one or more of a wide variety of terms - including transgender. Some of those terms are defined below. Use the descriptive term preferred by the person. Many transgender people are prescribed hormones by their doctors to bring their bodies into alignment with their gender identity. Some undergo surgery as well. But not all transgender people can or will take those steps, and a transgender identity is not dependent upon physical appearance or medical procedures.
An older term that originated in the medical and psychological communities. Still preferred by some people who have permanently changed - or seek to change - their bodies through medical interventions, including but not limited to hormones and/or surgeries. Unlike transgender, transsexual is not an umbrella term. Many transgender people do not identify as transsexual and prefer the word transgender.
Used as shorthand to mean transgender or transsexual - or sometimes to be inclusive of a wide variety of identities under the transgender umbrella.
An adjective used by some people whose sexual orientation is not exclusively heterosexual (e.g. queer person, queer woman). Typically, for those who identify as queer, the terms lesbian, gay, and bisexual are perceived to be too limiting and/or fraught with cultural connotations they feel don't apply to them. Some people may use queer, or more commonly genderqueer, to describe their gender identity and/or gender expression (see non-binary and/or genderqueer below).
Acronym for lesbian, gay, bisexual, transgender, and queer. Sometimes, when the Q is seen at the end of LGBT, it can also mean questioning. LGBT and/or GLBT are also often used.
An umbrella term describing people born with reproductive or sexual anatomy and/or a chromosome pattern that can't be classified as typically male or female. Those variations are also sometimes referred to as Differences of Sex Development (DSD.)
An adjective used to describe people who do not experience sexual attraction (e.g., asexual person). A person can also be aromantic, meaning they do not experience romantic attraction.
A term used by some to describe people who are not transgender. "Cis-" is a Latin prefix meaning "on the same side as," and is therefore an antonym of "trans-." A more widely understood way to describe people who are not transgender is simply to say non-transgender people.
A term used to describe some people whose gender expression is different from conventional expectations of masculinity and femininity. Not all gender non-conforming people identify as transgender; nor are all transgender people gender non-conforming. Many people have gender expressions that are not entirely conventional – that fact alone does not make them transgender. Many transgender men and women have gender expressions that are conventionally masculine or feminine. Simply being transgender does not make someone gender non-conforming. The term is not a synonym for transgender or transsexual and should only be used if someone self-identifies as gender non-conforming.
Terms used by some people who experience their gender identity and/or gender expression as falling outside the categories of man and woman. They may define their gender as falling somewhere in between man and woman, or they may define it as wholly different from these terms.