adj. 25B6; adjective REGULAR, periodical, at fixed intervals, recurrent, recurring, repeated, cyclical, cyclic, seasonal; occasional, infrequent, intermittent, sporadic, spasmodic, odd.
PERIODIC
Meaning of PERIODIC in English
Concise Oxford thesaurus English vocabulary. Краткий оксфордский словарь английского языка тезаурус. 2012