Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ăquĭmĭnārĭum, ii, n. [aqua-manus] (post-class. for ăquaemănālis), a waterbasin, wash-basin, Dig. 34, 2, 19, § 12; 34, 2, 21 (Paul. Sent. 3, 6, has ăquĭmĭnāle, is, n.).