Lewis & Short

1. dētestātĭo, ōnis, f. [detestor].

  1. I. In relig. lang.
    1. A. Execration, cursing, detestation, Liv. 10, 38; Hor. Epod. 5, 89; Sen. Ep. 117 med.; Gell. 2, 6, 3; Vulg. Dan. 9, 11.
    2. B. A keeping off, averting, Plin. 15, 30, 40, § 135: scelerum, Cic. Dom. 55, 140.
  2. II. In judicial lang., a formal renunciation under oath: detestatio est denuntiatio facta cum testatione, Dig. 50, 16, 40; cf. detestor, no. II.
    So detestatio sacrorum, the solemn renunciation of the family sacred rites, and thereby of the gens itself, which in arrogatio was made by the son, Gell. 15, 27, 3; cf.: Liber (Servii Sulpicii) de sacris detestandis, id. 6, 12, 1.