# Periodic vs. Periodical - What's the difference?

### Wiktionary

Relative to a period or periods.

Having repeated cycles.

"cyclic"

Occurring at regular intervals.

Periodical.

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

"non-periodic"

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

"aperiodic"

Having a structure characterized by periodic sentences.

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

• Periodical (noun)

A publication issued regularly, but less frequently than daily.

• Periodical (noun)

A regularly issued thematic publication that contains the most current information in its field, often the primary means for communication of original scholarship or creative work at the cutting edge of research in its field.

Periodic.

Published at regular intervals of more than one day, especially weekly, monthly, or quarterly.

Of, or relating to such a publication.

### Oxford Dictionary

appearing or occurring at intervals

"the periodic visits she made to her father"

relating to the periodic table of the elements.

relating to a rhetorical period.

• Periodical (noun)

a magazine or newspaper published at regular intervals.

occurring or appearing at intervals; occasional

"she took periodical gulps of her tea"

(of a magazine or newspaper) published at regular intervals

"Britain's best periodical art magazine"

### Webster Dictionary

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.

• Periodical (noun)

A magazine or other publication which appears at stated or regular intervals.

### Princeton's WordNet

happening or recurring at regular intervals

recurring at regular intervals

recurring or reappearing from time to time;

"periodic feelings of anxiety"

• Periodical (noun)

a publication that appears at fixed intervals

happening or recurring at regular intervals

Periodical

1 hour ago
2 hours ago
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