perennial
/pəˈrenɪəl; pə`rɛnɪəl/ adj
1 lasting for a long time 长久的; 持久的
a perennial subject of interest 永恒的主题.
2 constantly recurring 一再的; 反覆出现的
aperennial problem 反覆出现的问题
perennial complaints一再的抱怨.
3 (of plants) living for more than two years （指植物）多年生的. perennial, n perennial plant 多年生植物
hardy perennials, ie plants that can normally tolerate frost 耐寒的多年生植物.