byssum Save Could not find byssi in Logeion dictionaries. byssi neuter genitive singular of byssum byssi feminine vocative plural, feminine genitive singular, feminine nominative plural of byssus See byssi in Morpho Gaffiot 2016 byssum, ī, n. , Isid. Orig. 19, 27, 4, v. le suivant.