periodic

¹ American  

[peer-ee-od-ik] / ˌpɪər iˈɒd ɪk /

adjective

1. recurring at intervals of time.

   periodic revivals of an interest in handicrafts.

2. occurring or appearing at regular intervals.

   periodic visits by doctors to the village.

3. repeated at irregular intervals; intermittent.

   periodic outbreaks of the disease.

4. Physics. recurring at equal intervals of time.

5. Mathematics. (of a function) having a graph that repeats after a fixed interval period of the independent variable.

6. Astronomy.

   1. characterized by a series of successive circuits or revolutions, as the motion of a planet or satellite.

   2. of or relating to a period, as of the revolution of a heavenly body.

7. pertaining to or characterized by rhetorical periods, or periodic sentences.

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periodic ² American  

[pur-ahy-od-ik] / ˌpɜr aɪˈɒd ɪk /

adjective

Chemistry.

1. of or derived from a periodic acid.

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periodic British  

/ ˌpɪərɪˈɒdɪk /

adjective

1. happening or recurring at intervals; intermittent

2. of, relating to, or resembling a period

3. having or occurring in repeated periods or cycles

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Other Word Forms

• periodicity
  noun
• periodically
  adverb

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Etymology

Origin of periodic¹

First recorded in 1635–45; from Latin periodicus, from Greek periodikós; see origin at period, -ic

Origin of periodic²

First recorded in 1830–40; per- + iodic

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Explanation

Something periodic happens only occasionally, after a "period" of time. Lunch happens every day, after 4th period, so it's safe to say it's periodic. Something periodic doesn't have to happen at regular intervals, though. The word "period" is the key to the meaning of periodic, because something periodic can happen only after a period of time. Periodic visits to the vet are a good way to make sure that your pet stays healthy. Why not just use "occasional," you ask. Good question. Periodic implies that the thing will continue to happen over and over—periodically. Like comets and victories by the Yankees. These things are reliable, if periodic.

Example Sentences

See Examples For:

periodic

The investments “symbolize skin in the game” and create windows for periodic communications, he adds.

From The Wall Street Journal ● Nov. 11, 2026

Data Cymru also introduced periodic account reviews and strengthened account access controls, including using multi-factor authentication.

From BBC ● Oct. 21, 2026

Frustration has boiled over into periodic calls to end fraternities at Cornell altogether.

From The Wall Street Journal ● Oct. 16, 2026

The wildfire haze has drifted into nearby Singapore, Malaysia, East Timor and even the Philippines, prompting periodic school closures and health warnings.

From Barron's ● Oct. 15, 2026

Countless similar oddities result from our conventional ways of measuring, reporting, and com paring periodic quantities, whether they be the monthly cash flow of a government or the regular daily fluctuations in body temperature.

From "Innumeracy: Mathematical Illiteracy and Its Consequences" by John Allen Paulos

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Related Words

• annual
• intermittent
• monthly
• occasional
• recurrent
• recurring
• regular
• repeated
• routine
• seasonal
• sporadic
• weekly
• yearly

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