Tosafot, Babylonian Talmud, Yevamot 76a, s.v. mesolelot
1 א
תוספות, תלמוד בבלי יבמות עו.
2 ב
פירש ריב"ן מטילות שכבת זרע שקבלו מבעליהן
The Rivan explained that nashim hamesolelot means women who receive the seed of their husbands and exchange it with each other. [Translation by Rabbi Steven Greenberg]
3 ג
Time Period: Rabbinic (Maccabees through the Talmud)