A navigational aid for sailors and pilots, which is distinctively marked to maximize its visibility in daylight.
Late 17th century; earliest use found in Edmund Gibson (1669–1748), bishop of London.
英语词典包含464360条英英释义在线翻译词条，基本涵盖了全部常用单词的英英翻译及用法，是英语学习的有利工具。