noun

1. A perennial plant; a plant that is active throughout the year or survives for more than two growing seasons.

adjective

1. Lasting or remaining active throughout the year, or all the time.

   “a perennial stream”

2. (of a plant) Having a life cycle of more than two years.

3. Continuing without cessation or intermission; perpetual; never failing.

Synonyms: everlasting, perpetual, timeless, permanent, perpetual, unceasing, recurring, repetitious