jac·ta·tion \jakˈtāshən\noun (-s) Etymology: Latin jactation-, jactatio, from jactatus (past participle of jactare) + -ion, -io -ion 1.: boastful declaration or display < one of his familiar jactations of imperfection — George Saintsbury > 2.[probably from French, from Latin]: a throwing or tossing of the body; specifically: jactitation