Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
nūgātōrĭus, a, um, adj. [nugator], trifling, worthless, useless, futile, nugatory: nugatoriae artes, i. e. lies, Plaut. Trin. 4, 2, 2: boves Ligustici, worthless, useless, Varr. R. R. 2, 5, 9; so, unguentum, id. L. L. 7, § 64 Müll.: ad probandum res infirma nugatoriaque, Cic. Caecin. 23, 64: illud valde leve est ac nugatorium, id. Fam. 11, 2, 3: in malā nugatoriāque accusatione, id. Rosc. Am. 15, 42: genus argumentationis, not to the point, Auct. Her. 2, 20, 31: genus deorum, Aug. Civ. Dei, 4, 27.
As subst.: nū-gātōrĭus, ii, m., a worthless fellow, nugatorium vocant, Sen. Ep. 36, 2.
Hence, adv.: nūgātōrĭē, triflingly, frivolously: tenuiter et nugatorie respondere, Auct. Her. 4, 36, 48.