Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
hŭmātĭo, ōnis, f. [humo], a burying (very rare; cf.: sepultura, funus, exsequiae): de humatione et sepultura dicendum, Cic. Tusc. 1, 43, 102: locus qui recipiat humationem, Dig. 43, 24, 22, § 4.