improperus
Could not find improperae in Logeion dictionaries.
improperae feminine vocative plural, feminine dative singular, feminine nominative plural, feminine genitive singular of improperus
imprŏpĕrus (inpr-), a, um, adj. [2. in-properus],
- not hasting, slow: sorores, Sil. 3, 96.
improperus, a, um (in u. properus), langsam, zögernd, Sil. 3, 96.
imprŏpĕrus, a, um, qui ne se hâte pas : Sil. 3, 96.