Periodic vs. Periodically — What's the Difference?

Appearing or occurring at intervals

From time to time; occasionally

Relating to the periodic table of the elements.

Having or marked by repeated cycles

Relating to a rhetorical period.

Happening or appearing regularly or from time to time

Having or marked by repeated cycles

Characterized by periodic sentences.

Happening or appearing regularly or from time to time

In a manner that is regular or periodic.

Characterized by periodic sentences.

Intermittently or recurrently

Relative to a period or periods.

In a periodical manner.

Having repeated cycles.

In a sporadic manner;

Occurring at regular intervals.

Periodical.

(astronomy) 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 $k>1$.

(rhetoric) Having a structure characterized by periodic sentences.

Relating to the highest oxidation state of iodine; of or derived from a periodic acid.

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

Of or pertaining to a period or periods, or to division by periods.

Performed in a period, or regular revolution; proceeding in a series of successive circuits; as, the periodical motion of the planets round the sun.

Happening, by revolution, at a stated time; returning regularly, after a certain period of time; acting, happening, or appearing, at fixed intervals; recurring; as, periodical epidemics.

Of or pertaining to a period; constituting a complete sentence.

Happening or recurring at regular intervals

Recurring at regular intervals

Recurring or reappearing from time to time;