[{"Bold_text": "noun", "List Items": ["an apparatus for conveying information by means of visual signals, as a light whose position may be changed.", "any of various devices for signaling by changing the position of a light, flag, etc.", "a system of signaling, especially a system by which a special flag is held in each hand and various positions of the arms indicate specific letters, numbers, etc."]}, {"Bold_text": "verb (used with or without object)", "List Items": ["to signal by semaphore or by some system of flags."]}]