1. adjective /pəˈɹɛniəl/
a) Lasting or remaining active throughout the year, or all the time.
a perennial stream
b) (of a plant) Having a life cycle of more than two years. Compare , .
The perennial existence of bodies corporate and their fortunes are things particularly suited to a man who has long views…
2. noun /pəˈɹɛniəl/
A perennial plant; a plant that is active throughout the year or survives for more than two growing seasons. Compare , .
Wikipedia foundation.