Lewis & Short

ob-dulco, 1, v. a., to sweeten, make sweet (post-class.): aliquid sale, Cael. Aur. Tard. 3, 8, 146; 4, 1, 12: fauces, Ambros. Hexaëm. 5, 12: obdulcatus panis, Cael. Aur. Tard. 3, 8 med.: fontes amari obdulcati, Vulg. Judith, 5, 15.