Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
The word acusticus could not be parsed. Trying a normal dictionary lookup:
No entries found. Showing closest matches:
1. ăcus, ūs, f. [cf. 2. acer].
2. ăcus, ĕris, n. (also, ūs, f., v. 1. acus, III.) [kindred with acus, ūs, Goth. ahana, old Norse agn, old Germ. Agana], = ἄχυρον, the husk of grain and of pulse; chaff, Cato, R. R. 54, 2; Varr. R. R. 1, 52; 57; 3, 9, 8.
3. ăcus, i, m. [1. acus], a kind of sea-fish with a pointed snout, the hornpike or gar-pike (Gr. βελόνη): acus sive belone unus piscium, etc., Plin. 9, 51, 76, § 166: et satius tenues ducere credis acos, Mart. 10, 37, 6; cf. Plin. 32, 11, 53, § 145, where belonae again occurs. (Some read una for unus in the passage from Plin., and acūs for acos in Mart., as if these forms belonged to 1. acus.)
Ăcūsĭlas, ae, m. [from Ἀκουσίλαος], an Argive historian, Cic. de Or. 2, 12, 53.