screen door

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun US A light door of mesh, outside of another door, used to prevent ingress by insects.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a door that consists of a frame holding metallic or plastic netting; used to allow ventilation and to keep insects from entering a building through the open door