Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
irrĕmĕābĭlis (inr-), e, adj. [2. in-remeabilis], from which one cannot return, irremeable (poet.): error, Verg. A. 5, 591: via, Sen. Herc. Fur. 548: unda, i. e. the Styx, Verg. A. 6, 425: litus, Sil. 5, 41.