/ˌpɪəriˈɒdɪk ||; ˌpɪrɪˈɑdɪk/(also periodical /-kl ||; -kḷ/) adj happening fairly regularly 定期的;定期发生的: We have periodic meetings to check on progress.我们定期开会检查进展情况。 ➔periodically /-kli ||; -klɪ/ advAll machines need to be checked periodically.所有机器都需要定期检查。