Adjective

(-)

Relative to a period or periods.

Having repeated cycles.

*{{quote-book, year=1899, author=(Stephen Crane)

, title=, chapter=1 , passage=There was some laughter, and Roddle was left free to expand his ideas on the periodic visits of cowboys to the town. “Mason Rickets, he had ten big punkins a-sittin' in front of his store, an' them fellers from the Upside-down-F ranch shot 'em up […].”}}

Occurring at regular intervals.

Periodical.

(label) Pertaining to the revolution of a celestial object in its orbit.

For which any return to it must occur in multiples of $k$ time steps, for some $k>1$.

(label) Having a structure characterized by periodic sentences.

(label) Relating to, derived from, or designating, the highest oxygen acid (HIO) of iodine.

Adjective

(-)

Of or derived from a periodic acid.