A metal awning window esp. designed for institutions of detention. The sashes (ventilators, 2) are only 6 in. (15 cm) to 8 in. (20 cm) high and pivot on full-width hardened steel rods about 1 in. (2.5 cm) in diameter.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.