a.[Z]

1. 终年的，常年的
2. 长期的，不断的；常在的
   the perennial shortage of capital

   资金的长期短缺

3. 反复的；一再的
4. 【植】多年生的

n.

1. 多年生植物[C]

adj.

1. lasting for a long time; enduring or continually recurring.
   ▸continually engaged in a specified activity:

   a perennial student.
2. (of a plant) living for several years. Compare with annual, biennial.
3. (of a stream or spring) flowing throughout the year.

n.