testātĭo (noun F) : ōnis. testor.
* A bearing witness (whether orally or in writing), a giving testimony, attesting, testifying (not in Cic., but cf. testificatio), Dig. 22, 4, 4; 3, 2, 21; 48, 19, 9; 48, 10, 1; Quint. 5, 7, 32; 5, 13, 49; 12, 3, 5 al.
* A calling to witness, invoking as witness: inter foederum ruptorum testationem,i.e. during an invocation of the gods as witnesses,Liv. 8, 6, 3 (cf. id. 8, 6, 1).