[{"Bold_text": "noun", "List Items": ["a person or thing that scans .", "Also calledop·ti·cal read·er[op, -ti-k, uh, l , ree, -der],.Computers.a device that scans printed, handwritten, barcode, or other visual data and encodes it into digital format. optical scanning optical scanning.", "Photography.any device for exposing an image on film, a sensitized plate, etc., by tracing light along a series of many closely spaced parallel lines.", "(in aerial photography) a device for estimating the ratio of aircraft speed to aircraft altitude.", "a photoelectric device for scanning picture to determine automatically the density of the hue or value in each area for transmission by wire or radio or for preparation of color process printing plates.", "a computer-aided electronic system using photoelectric cells to separate copy, as color illustrations, into its primary colors, correct color copy, and produce a set of color separations ready for proofing or printing.", "Radio.a radio receiver, used especially by police, firefighters, and the press, that continuously tunes to preselected frequencies, broadcasting any signal that it detects.", "Medicine/Medical, Biology.a device for examining a body, organ, tissue, or other biologically active material. CAT scanner CAT scanner, MR scanner MR scanner, PET scanner PET scanner, sonogram ."]}]