Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
mūgĭnor, āri, v. dep., to dally, trifle, hesitate, delay (rare but class.): muginari est nugari et quasi tarde conari, Paul. ex Fest. p. 147 Müll.: muginamur, Lucil. ap. Non. 139, 6; Att. ib. 139, 7: dum tu muginaris, cepi consilium domesticum, Cic. Att. 16, 12, 1.
In the collat. form, mūsĭnor, āri: dum ista (ut ait M. Varro) musinamur. Plin. H. N. prooem. § 18.