Müllerian or Mullerian is an alternate term for a female, female-like, or those whose fetal development favored the Müllerian or paramesonephric ducts. It is typically defined as an individual who has various female bodily traits, though the original definition broadly describes it as individuals whose development favored the Müllerian ducts, which typically leads to the creation of a vagina.

The original definition encompasses those who may be infertile, altersex, and those with ambiguous genitalia.

The more specific definition however includes the requirement to produce eggs via ovaries, having a higher production of estrogen, having larger breasts, and the ability to become impregnant.[1]


The term was originally suggested by a transgender woman in the early 2010s to describe individuals whose development favored the Müllerian ducts.[1] The term was popularized by Tumblr user acro-pluris in 2018 and redefined by Tumblr user mourningmogaicrew to be more specific.[2][3]

Related Terms

Label Relationship Description Difference
AFAB Similar Individuals who were assigned female at birth based on external sex characteristics. Müllerian is a type of bodily sex, whereas AFAB is the legal assignment of one's sex.
Wolffian Counterpart Alternate term for biological male. Wolffian is the masculine counterpart.

Flags and Symbols

The flag was created by Tumblr user mourningmogaicrew on August 31, 2021. The symbol was created by the same user on the same day and was based off the female symbol.[3]


  1. 1.0 1.1 mogai-ringo. “🌟Astrogods🌙.” Tumblr, mogai-ringo.tumblr.com/post/665433167091662848/yo-i-originally-saw-a-trans-woman-propose. Accessed 30 June 2023.
  2. arco-pluris. “Biosex Adjective Glossary.” Tumblr, 29 July 2018, arco-pluris.tumblr.com/post/176422613517/biosex-adjective-glossary-these-biosexual. Accessed 30 June 2023.
  3. 3.0 3.1 mourningmogaicrew. “Wolffian and Müllerian Flags/Symbols.” Tumblr, 1 Aug. 2021, mourningmogaicrew.tumblr.com/post/661062411443437568/wolffian-and-m%C3%BCllerian-flagssymbols. Accessed 30 June 2023.