Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
postillā, or separate, post illa, adv. [cf. postea], after that, afterwards (anteclass. and poet.): postilla, germana soror, errare videbar, Enn. ap. Cic. Div. 1, 20, 40 (Ann. v. 42 Vahl.): saepe post illa operam rei publicae fortem perhibuit, Cato ap. Gell. 3, 7: sed eum, qui mihi vendidit illam, numquam postilla vidi, Plaut. Curc. 4, 2, 43; id. Most. 1, 2, 61; Ter. Phorm. 2, 2, 33; Cat. 84, 9.