Pronunciation: (pēr"ē-od'ik),[key] —adj. 1. recurring at intervals of time: periodic revivals of an interest in handicrafts. 2. occurring or appearing at regular intervals: periodic visits of a mail steamer to an island. 3. repeated at irregular intervals; intermittent: periodic outbreaks of the disease. 4. Physics.recurring at equal intervals of time.
5. Math.(of a function) having a graph that repeats after a fixed interval (period) of the independent variable.
6. Astron. a. characterized by a series of successive circuits or revolutions, as the motion of a planet or satellite.
b. of or pertaining to a period, as of the revolution of a heavenly body.
7. pertaining to or characterized by rhetorical periods, or periodic sentences.
Pronunciation: (pûr"ī-od'ik),[key] —adj.Chem. of or derived from a periodic acid.