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