形容詞 off-peak:

1. of a period of less than maximal use or demand or activity

off-peak

adj.（形容詞）
Not in the period of most frequent or heaviest use:
非高峰期的或非高峰期使用的：
例句：
lower rates for telephone calls made during off-peak hours; travelers who take advantage of off-peak fares.
在電話非高峰使用段時實行的低收費；利用交通低峰（非高峰）時的低收費標準旅行的旅客