perennial

Lasting an indefinitely long time; enduring.

Appearing again and again or year after year; recurrent: synonym: continual.

Living three or more years.

Lasting or active throughout the year.

A perennial plant.

Something that recurs or seems to recur on a yearly or continual basis.

Lasting or continuing without cessation through the year, or through many years: as, a perennial spring or fountain.

Continuing without stop or intermission; perpetual; unceasing; never-failing; everlasting.

In zoology, growing continually: noting teeth which have the pulp-cavity open, and grow indefinitely from persistent pulps: as, the perennial incisors of a rodent.