Lewis & Short

cŏhorto, āre, 1, v. a. (rare collat. form of cohortor), to exhort, encourage: et dicerent castra capta esse, atque hos cohortarent uti maturarent, Quadrig. ap. Non. p. 472, 19: exercitus pransus, paratus, cohortatus, Cat. ap. Gell. 15, 13, 5; v. cohortor.