a magazine or newspaper published at regular intervals 期刊
adjective
[attrib.]occurring or appearing at intervals; occasional 不时出现(或发生)的;偶尔的 she took periodical gulps of her tea. 她时不时地猛喝一大口茶。 ■(of a magazine or newspaper) published at regular intervals (杂志,报纸)定期出版的 Britain's best periodical art magazine. 英国最好的定期出版的艺术杂志。