Mars was usually regarded as a harbinger of rebellion, lawlessness, disease, and death. At most times Mars moves eastward with respect to the background stars. During a retrograde loop, the planet will move backwards in that respect, or retrograde.
熒惑指火星，有眩惑之意，多指悖亂、殘賊、疾喪等惡兆，與古希臘將火星視為戰神、可能為人類帶來災難的星占說法不謀而合。