Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
1. aspersus (adsp-), a, um, Part. of aspergo.
2. aspersus (adsp-, Jan), ūs, m. [aspergo], a sprinkling upon (used only in the abl., and perh. only in Plin.): calidae aquae adspersu, Plin. 8, 37, 56, § 134: insecta olei adspersu necantur, id. 11, 53, 115, § 279: aceti adspersu, id. 13, 12, 26, § 82 al.