Lewis Short
(adverb) : certātim, certatus, 2. certo
* Emulously, earnestly, eagerly (class. in prose and poetry): certatim de alicujus salute dicere,Cic. Sest. 34, 74; Liv. 1, 54, 3: mulieres puerique saxa et alia... certatim mittere,Sall. J. 67, 1: certatim alter alteri obstrepere,Liv. 1, 40, 6: hoc Cicero atque Asinius certatim sunt usi, * Quint. 6, 1, 21: currere,Cic. Phil. 2, 46, 118: ascendere,Liv. 26, 44, 9: exsurgere,Tac. A. 3, 65: erumpere curiā,id. ib. 12, 7: amare aliquem, * Plin. Ep. 2, 9, 5; cf. Suet. Aug. 100; id. Tib. 70; id. Calig. 57; id. Ner. 7; id. Vit. 15; and in poetry, * Cat. 64, 392; Verg. G. 1, 385; 4, 38; id. A. 3, 290; 5, 778; 7, 146; * Hor. S. 1, 5, 17; Ov. M. 3, 244; 12, 241; Stat. S. 3, 1, 179 al.
Charlton T. Lewis, Charles Short, A Latin Dictionary