Baretti: A dictionary of the English and Italian languages
Átto, s. m.
1. act, action, deed, feat; 2. manner, address, mien, carriage, deportment; 3. grin, grimace; 4. sign, signal; 5. act of an agent;6. affectation, airs; 7. act, division of a dramatic piece; 8. pl. records, papers and other documents appertaining to a law suit. Mettere in —, to reduce to practice, to put in operation, to begin to act.
Florio: a worlde of wordes, or most copious, dictionarie in Italian and English
atto: an act, a deed, an action. Also a gesture, a part, a tricke. Also apt, meet, ready, fit, prone, able, prepared. Also so much land as two oxen can plough in one tract without resting.