ASL STEM

Definition

1. An opaque shield placed above or around the screen of a cathode-ray tube to eliminate extraneous light. 2. A protective covering, usually providing special ventilation to carry away objectionable fumes, dusts, and gases, in which dangerous chemical, biological, or radioactive materials can be safely handled.

Source: McGraw-Hill Dictionary of Scientific and Technical Terms. New York: McGraw-Hill, 2003. Credo Reference. Web. 08 August 2012.