Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ostĭŏlum, i, n. dim. [ostium], a little door (post-Aug.), Col. 8, 14, 1: ostiola olitoria, Plin. 19, 8, 38, § 125: abscondita, Vulg. Dan. 14, 20.