noun, noun which may take the genitive case particle 'no'
weekly publication; weekly (magazine, etc.)
Refers to a periodical published once a week, or used attributively to mean 'weekly' (e.g., 週刊誌 = weekly magazine).
This weekly magazine goes on sale every Wednesday.
彼は週刊のニュースレターを購読している。
He subscribes to a weekly newsletter.
This magazine is published weekly.
The magazine changed from weekly to monthly.
週刊 means a weekly publication, while 季刊 means a much less frequent quarterly one, so learners can mix up which term matches which schedule.