Lewis Short
ărātĭo (noun F) : aro.
* A ploughing, and in gen. the cultivation of the ground, agriculture: iteratio arationis peracta esse debet, si, etc.,Col. 11, 2, 64: aratione per transversum iterata,Plin. 18, 20, 49, § 180: ut quaestuosa mercatura, fructuosa aratio dicitur,Cic. Tusc. 5, 31, 86.
* Meton. (abstr. for concr.), ploughed land, Plaut. Truc. 1, 2, 47 (cf. aratiuncula): (calsa) nascitur in arationibus,Plin. 27, 8, 36, § 58.— Esp., in Roman financial lang., the public farms or plots of land farmed out for a tenth of the produce (cf. arator, I. B.), Cic. Phil. 2, 39 fin.; Cic. Verr. 2, 3, 98.
Charlton T. Lewis, Charles Short, A Latin Dictionary