释义
a. 周期的,定期的
例句
1. The doctor made periodic visit to the house to see if the baby was all right. 医生定期到这家进行拜访，检查婴儿有没有问题。 2. The quality or state of being periodic; recurrence at regular intervals. 周期性周期出现的性质或状态；以固定的间隔而发生