Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
exoptābĭlis, e, adj. [exopto], desirable, desired (rare): nuntius, Plaut. Stich. 2, 2, 67: tempus, Sil. 11, 387: amico, Lucil. Sat. 26, 5.