Lewis & Short

ămārĭco, āvi, ātum, āre, v. a. [amarus], to make bitter (eccl. Lat.).

  1. I. Lit.: (liber) faciet amaricari ventrem tuum, Vulg. Apoc. 10, 9; 10, 10.
  2. II. Trop., to excite, to irritate: ecce repulsi sunt, qui amaricant, Aug. Enn. in Psa. 65, n. 15.