Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pōtābĭlis, e, adj. [poto], that may be drunk, drinkable, potable (post-class.), Aus. Clar. Urb. 14, 31: medicamina, Cael. Aur. Tard. 1, 4, 112: fons, Amm. 18, 9, 2.