psimmythium
Could not find psimithii in Logeion dictionaries.
psimithii Noun: neuter genitive singular of psimmythium
psimmȳthĭum or psimithĭum, ĭi, n., = ψιμμύθιον,
- white-lead, ceruse, = cerussa, Plin. 34, 18, 54, § 175.
psimmўthĭum (psīmī-), ĭī, n. (ψιμμύθιον), c. cerussa : Plin. 34, 175.