The terminology below can be used when covering trans stories. As a general rule the wishes of the individual being described should be prioritised and respected. If you do not know how to refer to somebody, ask them.
This list does not aim to be an exhaustive list of terminology used within the trans community.
Gender traditionally refers to a social and cultural construct of being a man or a woman. However some people do not identify within the gender binary of man/woman. Gender exists independently of sex, and an individual’s gender does not always correspond with the sex assigned at birth.
(See: Gender Identity, Sex)
Gender Identity is a person’s inner sense of their gender. For trans 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), but for some people it does not fit neatly into one of those two choices. Unlike gender expression, gender identity is not visible to others.
(See: Gender Expression, Transgender, Genderqueer)
Sex is the classification of people as male or female. At birth infants are assigned a sex, usually based on the appearance of their external anatomy. However a person’s sex, as defined by biology, is a combination of bodily characteristics including: chromosomes, hormones, internal and external reproductive organs, and secondary sex characteristics. Persons whose biological sex cannot be classified as either male or female are classified as intersex, however they may identify as intersex persons, male, female, trans persons, or other.
Transgender or Trans is an umbrella term which includes those people who have a gender identity which is different to the gender assigned at birth, and those people who wish to portray their gender identity in a different way to the gender assigned at birth. Transgender includes those people who feel they have to, or prefer to, or choose to, whether by language, clothing, accessories, cosmetics or body modification, present themselves differently to the expectations of the gender role assigned to them at birth. This includes, among many others, transsexual and transgender people, transvestites, cross dressers, no gender, multigender, genderqueer people, intersex, and gender variant people who relate to or identify as any of the above.
n.b: do not use transgendered, and always use the descriptive terms preferred by the individual. Trans identity is not dependent upon medical procedures.
Cisgender or Cis is a term used to describe non-trans people. It is used in the same way as heterosexual is used to mean non-homosexual.
Depathologisation of trans identities, means that being trans should no longer be viewed or characterised as psychologically abnormal. Currently trans identities are listed as a mental disorder in the World Health Organisation’s International Classification of Diseases.
Gender Expression is the external manifestations of gender, expressed through a person’s name, pronouns, clothing, haircut, behaviour, voice or body characteristics. Society identifies these cues as masculine or feminine, although what is considered masculine and feminine changes over time and varies by culture.
Genderqueer or Gender-fluid or Non-binary describe a person who does not identify with the male/female binary but somewhere outside or between. Some genderqueer people use neutral pronouns like “they” and “them”.
The term Intersex refers to people born with bodies that do not fit the normative definitions of male or female.
Legal Gender Recognition is the official procedure to change a trans person’s name and gender identifier in official registries and documents such as their birth certificate, ID card, passport or driving license. In some countries, it’s impossible to have your gender recognised by law. In other countries, the procedure is often long, difficult and humiliating.
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. For example transgender people may be straight, lesbian, gay, or bisexual.
Transsexual is an older term that originated in the medical and psychological communities. The term is still preferred by some people who have permanently altered – or seek to alter – their bodies through medical interventions (including but not limited to hormones and/or surgeries). Unlike transgender or trans, transsexual is not an umbrella term. It is best to ask which term an individual prefers. If preferred, use as an adjective: transsexual woman or transsexual man.
Transgender Man or Trans Man or FTM (Female to Male) are terms that may be used by people who were assigned female at birth but identify and live as men. Some may prefer to simply be called men, without any modifier. It is best to ask which term an individual prefers. 
Transgender Woman or Trans Woman or MTF (Male to Female) are terms that may be used by people who were assigned male at birth but identify and live as women. Some may prefer to simply be called women, without any modifier. It is best to ask which term an individual prefers. 
Transition includes some or all of the following personal, medical, and legal steps: telling one’s family, friends, and co-workers; using a different name and new pronouns; dressing differently; changing one’s name and/or sex on legal documents; hormone therapy; and possibly (though not always) one or more types of surgery. The exact steps involved in transition vary from person to person. 
Transphobia is a matrix of cultural and personal beliefs, opinions, attitudes and aggressive behaviours based on prejudice, disgust, fear and/or hatred directed against individuals or groups who do not conform to, or who transgress societal gender expectations and norms. Transphobia particularly affects individuals whose lived gender identity or gender expression differs from the gender role assigned to them at birth, and it manifests itself in various ways, e.g., as direct physical violence, transphobic speech and insulting, discriminatory media coverage, and social exclusion. Transphobia also includes institutionalized forms of discrimination such as criminalization, pathologization, or stigmatization of non-conforming gender identities and gender expressions. 
 Definitions adapted from GLAAD Media Reference Guide – Transgender Issues see: www.glaad.org/reference/transgender
 Adapted from TENI Media Style Guidelines http://www.teni.ie/attachments/03b3edc9-7f31-4c8c-af7d-202c3d8cb238.PDF
 Definition from Organisation International Intersex (OII) Europe http://oiieurope.org/
 Definitions adapted from the Transrespect versus Transphobia Worldwide research project. See: www.transrespect.org