Lewis & Short

grădātim, adv. [gradus], step by step, by degrees, little by little, gradually (class.; syn.: sensim, paulatim, pedetentim): nihil ita pedetentim et gradatim tum accessus a te ad causam facti, tum recessus, ut, etc., Cic. Fam. 9, 14, 7: gradatim ascendere, id. de Or. 3, 61, 227; cf. id. Part. 15, 54: quid opus erat te gradatim istuc pervenire? Sumpsisses tuo jure. Quid autem est istuc gradatim? id. N. D. 1, 32, 89; cf.: gradatim respondens, id. Tusc. 1, 24, 57: ad pauciores deducere, id. ib. 2, 65, 164: cum gradatim sursum versus reditur, id. Or. 39, 135: captiosissimo genere interrogationis utuntur, cum aliquid minutatim et gradatim additur aut demitur, id. Ac. 2, 16, 49; Varr. R. R. 3, 5, 4; Plin. 33, 4, 21, § 76: quos non una ut dicitur pertica, sed distincte gradatimque tractavi, Plin. Ep. 8, 2, 8; Gell. 14, 7, 9: amicos habere, by gradations, i. e. of different grades, Plin. Ep. 2, 6, 2.