jactarius Save DMLBS jactarius [ML] 1 one who throws, heaps, or shifts. 1278 in iiij ~iis de sablone KR Ac 486/22 m. 2. 2 one who boasts or brags. jactuarius Osb. Glouc. Deriv. 283 (v. jactare 9a); a boster, ampullator, ~ius, pompator, jactator CathA.