Lewis & Short

jactātor, ōris, m. [jacto], one who makes an ostentatious display of himself, a boaster, braggart: rerum a se gestarum, Quint. 11, 1, 17: civilitatis, Suet. Claud. 35; Stat. Th. 6, 837; Gell. 18, 4, 1.
Poet., with inf.: ille sub hiberno somnos educere caelo Jactator, he boasts, Sil. 11, 403.