Lewis & Short

septŭennis (collat. form septennis, Capitol. M. Aurel. 21), e, adj. [septem-annus], of seven years, seven years old: nunc priusquam septuennist (puer), Plaut. Bacch. 3, 3, 36; so, puer, id. Men. prol. 24; 5, 9, 57; id. Merc. 2, 2, 21; id. Poen. prol. 66; Prud. στεφ. 10, 656.