Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
Ăcĕsĭnēs, ae, m., = Ἀκεσίνης, a river in India, which falls into the Indus, now the Chenaub, Curt. 9, 3, 20; Mel. 3, 7, 6; Plin. 6, 20, 23 al.
† ăcĕsis, is f., = ἄκεσις, a sort of borax, used in medicine, Plin. 33, 5, 28, § 92.