noun, noun which may take the genitive case particle 'no'
monthly publication; monthly issue
Refers to a magazine, journal, or other periodical published once a month. Often used as a noun or with の to modify another noun.
This monthly magazine goes on sale on the 25th of every month.
He edits a monthly newsletter.
This magazine is published monthly.
The magazine is scheduled to switch to a monthly publication schedule next year.
月刊 is a publication issued once a month, while 年刊 is issued once a year, and the two are easily confused because they share the same structure (frequency + 刊).