perfamiliaris
From LSJ
δύο ἀρνήσεις μίαν συγκατάθεσιν ποιοῦσι → two negatives make an affirmative
Latin > English (Lewis & Short)
per-fămĭlĭāris: e, adj.,
I very intimate, very familiar (class.): perfamiliaris Philisto, Cic. Q. Fr. 2, 11 (13), 4.—In tmesi: Phaedon Socrati per fuit familiaris, Gell. 2, 18, 1.—
II Subst.: perfămĭlĭāris, is, m., a very intimate or familiar friend (class.): meus, Cic. Fam. 13, 51: Epicuri, id. Fin. 5, 31, 94: M. Antonii, id. Brut. 45, 168.