柯林斯詞典hard hat (hard hats) 1. N-COUNT A hard hat is a hat made from a hard material, which people wear to protect their heads on construction sites or in factories, or when riding a horse. 安全帽; 頭盔 返回 hard hat劍橋詞典a hat made of a strong substance that is worn by workers to protect their heads （建筑工人等戴的）安全帽 返回 hard hat