Lesbian

A lesbian was a female homosexual. A common stereotype for lesbians was short hair. (PROSE: Revolution Man) Homo- and lesbophobia were a huge issue in human culture before Bernice Summerfield's home era of the 26th century. By Benny's time, though she couldn't understand why people had made such a big deal of such things. (PROSE: Sky Pirates!)

Even by 2030, though there was an air of passivity, at least among some. Fiona, or Fee, commented, "Fine, if that's what turns them in," after being told two women were lesbians. (PROSE: Warchild)

According to the thoughts of a man using a telephone, as taken in by Toshiko Sato with the telepathy pendant, Marcus Farrer had sex with two lesbians. "How would it work? I mean, does one of them sort of have to sit..." (TV: Greeks Bearing Gifts)

Charles "Chick" Peters specifically did not identify as a lesbian, despite his "female" body and attraction to women, because he identified as a man. Chick was in fact born with XY chromosomes, and did not have a womb. (PROSE: Blue Box)

According to one account, Iris Wildthyme was a lesbian novelist from late 20th century Earth. (PROSE: Hospitality) In a universe where she was a Time Lady, Iris had a lesbian companion named Jenny Winterleaf. She described her to the Third Doctor as "the butch dyke traffic warden". (PROSE: Verdigris)

Bill Potts, a companion of the Twelfth Doctor, was attracted exclusively to women. (TV: The Pilot, Knock Knock, Extremis, The Eaters of Light) She eventually ended up with a girlfriend, Heather. (TV: The Pilot, The Doctor Falls)

Angstrom, an Albarian, was apparently married to another woman until she was killed by the Stenza. (TV: The Ghost Monument)

Horl and Katta were a lesbian couple. Barbara Wright taking a coy delight in pointing this out to an oblivious Ian Chesterton. (AUDIO: Tick-Tock World)

Shawna Thompson commented that "Harry Styles [was] an honorary lesbian as far as [she was] concerned". (AUDIO: Hysteria)

Whilst searching for Sea Devils, Jo Jones met Kat and Alex, who were a young lesbian couple. (WC: Defenders of Earth)

Najia Khan suspected that her daughter, Yaz, may be a lesbian, (TV: Arachnids in the UK) a possibility that Yasmin had trouble admitting, even to herself. (TV: Eve of the Daleks)

Behind the scenes
Fanart reposted by the official Doctor Who Twitter account for #FanArtFriday on 3 June 2022 depicted Yasmin Khan with face paint of the lesbian pride flag as well as a pin of the flag's colours in the shape of a rainbow. Although Yaz was implied and eventually confirmed to harbour romantic feelings for the Thirteenth Doctor on television, made explicit in Eve of the Daleks, her specific label was never otherwise discussed in BBC-licensed material.