periodic

Short definition from Wiktionary

Adjective

1. 1
   Relative to a period or periods.
2. 2
   Having repeated cycles.
3. 3
   Occurring at regular intervals.
4. 4
   Periodical.
5. 5
   Pertaining to the revolution of a celestial object in its orbit.
6. 6
   For which any return to it must occur in multiples of k time steps, for some k>1.
7. 7
   Having a structure characterized by periodic sentences.
8. 8
   Relating to the highest oxidation state of iodine; of or derived from a periodic acid.