a. belonging to or active during the night
a. of or relating to or occurring in the night
a. 夜的, 夜曲的
[医] 夜间的
1. Many animals, like owls, are nocturnal and are active at night.
许多动物，比如猫头鹰，是夜行动物，晚上活跃。
2. Nocturnal creatures have special adaptations to help them see in the dark.
夜行动物有特殊的适应能力，帮助它们在黑暗中看见东西。
3. I enjoy going for walks in the park at night to observe the nocturnal wildlife.
我喜欢在晚上去公园散步，观察夜间野生动物。