Ratiúncula, pen. cor. Diminut. Cic.A small reason: a little ac count or reckoning.Suggerere ratiunculas.Cic. -subducam ratiunculam, Quantillum argenti mibi apud trapezitam siet.Plaut.I wil recken or cast an account. &c.
Lewis and Short: Latin dictionary
rătĭuncula, ae, f.dim. [ratio]. I.A small reckoning, a little account: subduxi ratiunculam, Quantum aeris mihi sit, quantumque alieni siet, Plaut. Curc. 3, 1; id. Capt. 1, 2, 89; Ter. Phorm. 1, 1, 2.— II.A slight ground or reason: leves, Cic. Tusc. 4, 19, 43: huic incredibili sententiae ratiunculas suggerit, id. N. D. 3, 29, 73.—2. In dialectics, a petty syllogism: concludunt ratiunculas Stoici, Cic. Tusc. 2, 12, 29: humanis ratiunculis falsis contravenire conantur, Aug. Civ. Dei, 20, 1, 1.