ŏpīnātĭo, ōnis, f. [opinor],
a supposing , opining; a supposition , conjecture , imagination , fancy , opinion , belief (class.): opinationem volunt esse imbecillam assensionem, Cic. Tusc. 4, 7, 15; id. Ac. 2 ( Luc. ), 25, 78: haec autem opinatio est judicatio se scire, quod nesciat, id. Tusc. 4, 11, 26; cf. the context: mordax et inepta, Val. Max. 1, 8, 8: (Tullius) quid super tali opinatione sentiret, Arn. 3, 6.