Cisgender has officially been added into the Oxford English Dictionary.

Dating back to 1999, the adjective is defined as ‘designating someone whose sense of personal identity corresponds to the sex and gender assigned to him or her at birth. This word exists to serve as an equal and complement to transgender.’

Researchers at the OED were able to include the word after it was noted that it had been used in parliament.

Good to see "Cisgender" make the jump to the OED. I brought a @julianhuppert Hansard speech to the lexicographers attention as evidence.

— Jenny List (@Jenny_Alto) June 25, 2015

Makes my little heart leap with joy to hear Cisgender made the OED partly because of @julianhuppert using it in parliament.

— Sarah Brown (@auntysarah) June 25, 2015

Other words added include ‘twerk’, ‘half-ass’, ‘webisode’, ‘sext’ and ‘stanky’.

The historical dictionary also found that twerk, popularisd by gender-fluid bisexual singer Miley Cyrus, dates back to 1820.

Fiona McPherson, senior editor of Oxford English Dictionary, has said the new entries have ‘earned their place’ in the history of the English language.

In 2013, the OED updated the definition of marriage to include same-sex couples.