synthesinus
Could not find synthesinam in Logeion dictionaries.
synthesinam Adjective: feminine accusative singular of synthesinus
synthĕsĭnus, a, um, adj., = συνθέσινος,
- pertaining to a dressing-gown: vestis, i.e. a dressing-gown, Suet. Ner. 51 (v. the commentators ad loc.).