semimonthly publication; biweekly magazine
Refers to a magazine or journal published twice a month. Often used in the names of periodicals.
This semimonthly magazine is published on the 1st and 15th of each month.
週刊 means a weekly publication, more frequent than 半月刊.
Compound of 半 (half), 月 (month), and 刊 (publication).