Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
lasso, āvi, ātum, 1, v. a. [lassus], to render faint or languid, to tire, weary, fatigue, to deprive of vigor (syn.: fatigo, languefacio; perh. not ante-Aug.): aliquem, Cels. 1, 3, 1: laevam, Curt. 9, 5, 1: longior infirmum ne lasset epistola corpus, Ov. H. 20, 241: brachia plagis, Prop. 4 (5), 8, 67; cf.: lassata gravi ceciderunt brachia massā, Juv. 6, 421: visu lassatur inani, Val. Fl. 1, 707: oculos, Stat. Th. 5, 483: jam vitia primo fervore adulescentiae indomita lassavit, Sen. Ep. 68, 13; 70, 3; 88, 10; id. Clem. 1, 19, 4; Plin. 9, 10, 12, § 36; 30, 16, 53, § 149: numina, to weary with petitions, Luc. 5, 695: Cecropiam Cotytto, Juv. 2, 92.
Transf.: sidus Hyperborei Bootae, i. e. to bear steadfastly, Mart. 4, 3, 5: lassatum fluctibus aequor, i. e. become calm, Luc. 5, 703: ventus lassatur, id. 9, 453: lassata triumphis fortuna, id. 2, 727.
In mal. part., Tib. 1, 9, 55; Juv. 6, 129.
lassus, a, um, adj. [etym. dub.; acc. to Bopp, Gloss. 112, 6, for glassus from glasnus; kindred to Sanscr. glasnu, fessus, defessus, lassus; but more prob. collat. form of laxus; cf. langueo], faint, languid, weary, tired, exhausted (syn.: fessus, fatigatus, defatigatus; mostly poet. and in post-Aug. prose; not in Cic. or Cæs.).