1. Excision of any adnexa.
2. In gynecology, excision of the fallopian tube and ovary if unilateral and excision of both tubes and ovaries (adnexa uteri) if bilateral.

This plural Latin word is used in medicine in reference to appendages; for example, in gynecology the adnexa are the appendages of the uterus, namely the ovaries, Fallopian tubes (ducts or canals which conduct the ova from the ovaries to the uterus), and ligaments that hold the uterus in place.