### Definition of Periodic

1. Adjective. Happening or recurring at regular intervals. "The periodic appearance of the seventeen-year locust"

2. Adjective. Recurring or reappearing from time to time. "Periodic feelings of anxiety"
Exact synonyms: Occasional

### Definition of Periodic

1. a. Pertaining to, derived from, or designating, the highest oxygen acid (HIO&?;) of iodine.

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

### Definition of Periodic

1. Adjective. Relative to a period or periods. ¹

2. Adjective. Having repeated cycles. ¹

3. Adjective. Occurring at regular intervals. ¹

4. Adjective. Pertaining to the revolution of a celestial object in its orbit. ¹

6. Adjective. (rhetoric) Having a structure characterized by periodic sentences. ¹

7. Adjective. (mathematics stochastic processes of a state) for which any return to it must occur in multiples of $k$ time steps, for some $k>1$. ¹

8. Adjective. Of or derived from a periodic acid. ¹

¹ Source: wiktionary.com

### Definition of Periodic

1. recurring at regular intervals [adj]

### Medical Definition of Periodic

1. Recurring at regular intervals of time. Origin: Gr. Periodikos This entry appears with permission from the Dictionary of Cell and Molecular Biology (11 Mar 2008)

### Periodic Pictures

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### Lexicographical Neighbors of Periodic

 perinæalperinæumperiocularperiod doublingperiod of playperiod of timeperiod pieceperiod piecesperiodateperiodates periodedperiodentosisperiodic (current term)periodic-tableperiodic acidperiodic acid Schiff reactionperiodic apnea of the newbornperiodic arthralgiaperiodic biopolymerperiodic breathing periodic catatoniaperiodic cometperiodic diseaseperiodic eventperiodic feverperiodic filariasis

### Literary usage of Periodic

Below you will find example usage of this term as found in modern and/or classical literature:

1. Monographic Medicine by William Robie Patten Emerson, Guido Guerrini, William Brown, Wendell Christopher Phillips, John Whitridge Williams, John Appleton Swett, Hans Günther, Mario Mariotti, Hugh Grant Rowell (1916)
"periodic Family Paralysis Definition.—A periodic paralysis affecting members of ... Remarks upon the irregular and unusual types of familial periodic ..."

2. Theory of Functions of a Complex Variable by Andrew Russell Forsyth (1893)
"OF DOUBLY-periodic FUNCTIONS If A be zero, then E(z) is a doubly-periodic function of the first kind when es is unity, and it is a doubly-periodic function ..."

3. The Encyclopedia Americana: A Library of Universal Knowledge (1919)
"It must 'be remembered, throughout, that the "periodic law" is more or less elastic, and that in classifying the elements in groups we have to consider ..."

4. Nature by Norman Lockyer (1877)
"Also the secular variation of the element considered, that is, the rate of variation of the element when cleared of periodic inequalities, will be given by ..."

5. Journal of Nervous and Mental Disease by Philadelphia Neurological Society, American Neurological Association, Chicago Neurological Society, New York Neurological Association (1903)
"Under the term periodic Psychoses we understand attacks of mental derangement occurring at certain intervals, during which the patient is more or less free ..."

6. Journal of Nervous and Mental Disease by American Neurological Association, Philadelphia Neurological Society, Chicago Neurological Society, New York Neurological Association, Boston Society of Psychiatry and Neurology (1903)
"Under the term periodic Psychoses we understand attacks of mental derangement occurring at certain intervals, during which the patient is more or less free ..."

7. Pneumonia: Its Supposed Connection, Pathological and Etiological, with by René La Roche (1854)
"The success of the anti-periodic treatment in pneumonia—supposing it true—no proof of the, identity in question.—For these reasons, I am not prepared to ..."

8. A Course in Mathematical Analysis by Édouard Goursat, Earle Raymond Hedrick (1917)
"In the second case the integral 0j(x) alone is a doubly periodic function of ... The integral <^1(x) is again a doubly periodic function of the second kind, ..."