periodic
1. [ adjective ] happening or recurring at regular intervals
Synonyms: periodical
Related terms: aperiodic pulsed intermittent oscillatory cyclic
2. [ adjective ] recurring at regular intervals
Related terms: rhythmical
3. [ adjective ] recurring or reappearing from time to time
Examples:

"periodic feelings of anxiety"

Related terms: sporadic
Similar spelling:   periodical
  periodicity
  Perdicinae
  Perdicidae