The term 'uses a spyglass' can be summarized by the crossword solution PEERS, which is an acronym for Periscope Evaluation and Examination of Radar Signals. This term refers to the use of a periscope, which is an optical instrument used to observe objects that are otherwise out of sight. It is commonly used in military operations to observe enemy positions or movements. The spyglass is also used in navigation, astronomy, and other fields.