(1) 年(时)代，纪元 (period of time marked by an important event or events)[C]：the industrial/postwar～工业/战后时代; the～of the atom/computer/space travel/steam engine 原子/计算机/星际旅行/蒸汽机时代; an～of progress/of social reform 进步/社会改革的时代; be/live/usher in a great～of world peace 处于/生活在/迎来世界和平的时代; inaugurate/mark a new～开创/标志一个新时代; 〖同〗 period，age，time，interval;

(2) (地质)代 (one of the five very large divisions of time in geological history) [C]：the Cenozoic/Mesozoic/Paleozoic/Proterozoic/Archeozoic～新生代/中生代/古生代/原生代/太古代;

【辨异】era与age、period和epoch的区别见AGE。