Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
fĭdēlĭtas, ātis, f. [fidelis], faithfulness (as shown in one’s acts), trustiness, firm adherence, fidelity (class.; most freq. in Cic.): simplicem praeterea et communem et consentientem … eligi par est: quae omnia pertinent ad fidelitatem, Cic. Lael. 18, 65: quantum studio et fidelitate consequi potuit, id. Fam. 13, 16, 2: maxime operam et fidelitatem desideravi tuam, id. ib. 16, 12, 6; cf.: in hac fortuna perutilis ejus et opera et fidelitas esset, id. Att. 9, 17 fin.: amicorum, id. Phil. 12, 9, 22; cf. id. Planc. 29, 71 fin.; with benevolentia, id. Fam. 13, 20: fidelitas atque auxilia provinciae illius, Hirt. B. G. 8, 46 fin.: fides fidelitasque amicum erga, Plaut. Trin. 5, 2, 2: erga patriam fidelitas, Planc. in Cic. Fam. 10, 17, 2.