collactaneus
From LSJ
Latin > English (Lewis & Short)
col-lactānĕus: (conl-), a lacteo,
I a brother or sister nourished at the same breast, a foster-brother or sister (post-class.); masc., Gai Inst. 1, 39; Dig. 40, 2, 13; Inscr. Orell. 2281 al.; fem., Dig. 34, 4, 30, § 1 al.
Latin > French (Gaffiot 2016)
collactānĕus, ī, m., Dig. 40, 2, 13, collactĕus, ī, m., Hyg. Fab. 224 et collactĭcĭus, ĭī, m., CIL 8, 3523, frère de lait.