periodic
/ˌpɪərɪˈɒdɪk
/adjective
1Appearing or occurring at intervals: the periodic visits she made to her father...
- Despite this, he has continued to appear regularly at our periodic family gatherings, and is considered a family member in good standing.
- Each recommended practice is reviewed and revised as appropriate at regular periodic intervals.
- At periodic intervals, the iron bars at the mouth of narrow roads, put up to prevent the entry of heavy vehicles, are knocked down by lorries, due to reckless driving.
Synonyms
regular, periodical, at fixed intervals, recurrent, recurring, repeated, cyclical, cyclic, seasonal;
occasional, infrequent, intermittent, sporadic, spasmodic, odd
2 Chemistry Relating to the periodic table of the elements.The steadily increasing weights gave Mendeleyev, Meyer, and others a kind of index by which to order the elements and reveal their periodic behaviour....
- The study of oscillating reactions is the study of periodic changes in chemical reactions.
- The first rough draft of the periodic elements signaled not the end but the beginning of chemistry.
3Relating to a rhetorical period.However, in the late 18th century there was a return to the periodic Latinate style.
Origin
Mid 17th century: from French périodique, or via Latin from Greek periodikos 'coming round at intervals', from periodos (see period).