Baretti: A dictionary of the English and Italian languages
Spianáre, v. a.
1. to level, make level, smooth, or even. — in terra, to fling or throw flat upon the ground; 2. (met.) to declare, say openly, explain, expound, interpret; 3. to raze, lay even with the ground, pull down. — una fortezza,to raze or level a fortress. — il pane,to make bread. — i mattoni, to make bricks. — lo schioppo, to lower the musket in order to take aim. — in casa d'altrui, to consume every thing; 4. to place upon a level or upon an equality (applied to things generally). — costure,to smooth down the seams; (met.) to dress a person's jacket; v. r. to find their level (speaking of liquids).
Florio: a worlde of wordes, or most copious, dictionarie in Italian and English
spianare: to make plaine, to leuell. Also to explaine, to expound, to declare, to lay open. Also to raze or ruine any building flat to the ground.