Lewis & Short

taurŏbŏlĭor, ātus, v. dep. n. [id.].

  1. I. Lit., to make a sacrifice of a bull (taurobolium; late Lat.): matris deum sacra accepit et tauroboliatus est, Lampr. Heliog. 7; Inscr. Orell. 2351.
  2. II. Transf.: TAVROBOLIATA PETRA, set up to commemorate a taurobolium, Inscr. Orell. 2326.