Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
in-dĭsertus, a, um, adj., not eloquent (class.): Academicus, Cic. N. D. 2, 1, 1.
Of inanim. and abstr. things: prudentia, at a loss for words, Cic. de Or. 3, 35, 142.
Adv.: indĭsertē, not eloquently (rare but class.): orationem non indiserte collaudavit, Cic. Q. Fr. 2, 1, 3.