I. pe ‧ ri ‧ od ‧ ic AC /ˌpɪəriˈɒdɪk◂ $ -ˌpɪriˈɑː-/ BrE AmE ( also periodical ) adjective [only before noun]
happening a number of times, usually at regular times:
periodic home visits by nurses
—periodically /-kli/ adverb :
Teachers meet periodically to discuss progress.
II. pe ‧ ri ‧ od ‧ i ‧ cal AC /ˌpɪəriˈɒdɪk ə l $ ˌpɪriˈɑː-/ BrE AmE noun [countable]
a magazine, especially one about a serious or technical subject