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Synonyms

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.


periodic 2 American  
[pur-ahy-od-ik] / ˌpɜr aɪˈɒd ɪk /

adjective

Chemistry.
  1. of or derived from a periodic acid.


periodic British  
/ ˌpɪərɪˈɒdɪk, ˌpɪərɪəˈdɪsɪtɪ /

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

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Other Word Forms

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

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.

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Vocabulary lists containing periodic

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

The report also said free-range egg production should be discouraged in affected areas, and that there should be periodic potato testing in contaminated places too.

From BBC Jul. 21, 2026

If it does not comply, AliExpress risks periodic penalty payments.

From Barron's Jul. 20, 2026

The structure is a lattice located just beneath the surface of neurons and is known as the membrane-associated periodic skeleton, or MPS.

From Science Daily Jul. 15, 2026

Beijing’s targets now reach across the digital-defense periodic table: Gallium for semiconductors and radar.

From The Wall Street Journal Jul. 14, 2026

Throughout the nineteenth century, periodic waves of the disease sent more mortals than usual off to the world of spirits.

From "American Spirits" by Barb Rosenstock

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