assigned for some purpose. / taken out of agricultural production / reserved or booked in advance

To bring (something) into contact with the air, so as to freshen or dry it. / To let fresh air into a room or a building, to ventilate. / To discuss varying viewpoints on a given topic.

(biochemistry) That breaks down starch into maltose.

(philosophy) The principle that, if two objects are indistinguishable from one another with respect to all of their properties, then they are identical.