Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
calcānĕum, i, n. (calcānĕus, i, m., Isid. Orig. 11, 1, 14; Ambros. in Psa. 48) [calx] (a rare form for calx), the heel, Verg. M. 36: camelorum, Lampr. Elag. 20.