Lewis & Short

īrācundus, a, um, adj. [ira], irascible, irritable, passionate, choleric, angry, ireful, easily provoked (class.): iratus potest non esse iracundus: iracundus non potest aliquando iratus non esse, Sen. de Ira, 1, 4, 1 (al. om. non before potest): ut non tantum iratus sit sapiens, sed iracundus, id. ib. 2, 6, 3: sunt morosi et anxii et iracundi senes, Cic. de Sen. 18, 65: iracundum esse in aliquem, id. Planc. 26, 63: adversus hostes, Just. 7, 6, 15: quemadmodum posset leniri, Sen. de Ira, 1, 1, 1: tale non est ira, sed quasi ira, id. ib. 1, 2, 6: leones, Ov. M. 15, 86: mens, Lucr. 3, 296.
Comp.: iracundior est paulo, Hor. S. 1, 3, 29.
Sup.: iracundissimus, Sen. de Ira, 2, 6, 4; 2, 15, 1.
Transf. (poet.): neque patimur Iracunda Jovem ponere fulmina, easily provoked, held in readiness to fall, Hor. C. 1, 3, 40.
Adv. in two forms.

    1. 1. īrācundē, angrily, passionately: agere cum aliquo, Cic. Phil. 8, 5, 16; Just. 12, 6, 6; Plin. 11, 37, 54, § 143.
      Comp.: iracundius docere, Cic. Rosc. Com. 11, 31.
    2. 2. īrācundĭter, angrily, passionately: rem agere, Caecil. ap. Non. 11, 45; Enn. ap. Prisc. p. 1010 P.