a natural system in living things that controls regular physical activities such as sleeping 生物钟;生理钟 - (figurative)
At 35, Kate's biological clock was ticking (= she was beginning to think that she would soon be too old to have children). 到 35 岁时,凯特的生物钟开始滴答作响(开始觉得很快就会年龄大得不宜生育了)。 The movements of the leaves are triggered by the plant’s biological clock. 叶子的运动是由植物的生物钟触发的。 With jet lag, your biological clock is out of synch with the actual time. 因为时差的缘故,你的生物钟与实际时间不同步了。
- (figurative)