ŏpĭcus, a, um, adj. [a fuller form for Opsus, Obscus, and Oscus, lit. Oscan; cf. Paul. ex Fest. p. 188 Müll.; hence, transf.],
clownish , rude , stupid , ignorant , foolish (not in Cic.): (Graeci) nos quoque dictitant barbaros et spurcius nos quam alios opicos appellatione foedant, M. Cato ap. Plin. 29, 1, 7, § 14: ut nostri opici putaverunt, Gell. 13, 9, 4: chartae, rough , coarse , unpolished , Aus. Prof. 22: amica, Juv. 6, 454: opici mures, barbarians of mice , that gnaw books, id. 3, 207.
opicus adj., Oscan; hence, clownish, rude, stupid: amica, Iu.: mures, Vandals of mice, I...
An Elementary Latin Dictionary