modified
noun
See periodical in Webster's New World Roget's A-Z Thesaurus II
Happening or appearing at regular intervals:
cyclic, cyclical, isochronal, isochronous, periodic, recurrent. Idiom: like clockwork. See repetitionHappening or appearing now and then:
fitful, intermittent, occasional, periodic, sporadic. (Informal) on-again, off-again. See continueLearn more about periodical