Lewis & Short

fīdūcĭārĭus, a, um, adj. [id. II. B.].

  1. I. Jurid. t. t., of or relating to a thing held in trust, fiduciary: heres, that receives any thing in trust, Dig. 36, 1, 46; Inscr. Orell. 3524: tutela, Just. Inst. 1, 19; cf. Gai. Inst. 1, 172.
  2. II. Transf. beyond the jurid. sphere, intrusted, given, or held in trust: optimum ratus, eam urbem Nabidi veluti fiduciariam dare, Liv. 32, 38, 2: opera, * Caes. B. C. 2, 17, 2: regnum, Auct. B. Alex. 23, 2: imperium, Curt. 5, 9, 8.