Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
salmăcĭdus, a, um, adj. [contr. from salgama, salma, and acidus], of water, having a salt and sour taste, salso-acid: salmacidum ἁλμυρόν, salmacidus ἁλμυρός, ἁλώδης, Gloss. Philox. (post-Aug.): aquae (with nitrosae), Plin. 31, 3, 22, § 36: aqua (opp. dulcis), Plin. Val. 5, 41 fin.: fluvii, Flor. 4, 10, 8.