infidelitas
From LSJ
ἥλιον ἐν λέσχῃ κατεδύσαμεν → we let the sun go down in talk, we let the sun go down in conversation
Latin > English (Lewis & Short)
infĭdēlĭtas: ātis, f. infidelis,
I unfaithfulness, faithlessness, infidelity: amicitiarum, Cic. Tusc. 5, 22: infidelitatis suspicionem sustinere, * Caes. B. C. 2, 33. — In <number opt="n">plur.</number>: quantae infidelitates in amicitiis, Cic. Mil. 26, 69.