Periodic
Part of speech: adjective
Definition: Relative to a period or periods. Having repeated cycles. Occurring at regular intervals. Pertaining to the revolution of a celestial object in its orbit. periodical Having a structure characterized by periodic sentences. Of or derived from a periodic acid.
Example sentence: The universal human laws - need, love for the beloved, fear, hunger, periodic exaltation, the kindness that rises up naturally in the absence of hunger/fear/pain - are constant, predictable, reliable, universal, and are merely ornamented with the details of local culture.
Intermittent
Part of speech: adjective
Definition: Stopping and starting at intervals; coming after a particular time span; not steady or constant