monthly
adv.
1530s, from month + -ly(2). As an adjective from 1570s. Old English had monaþlic, but the modern words seem to be separate formations.
〔李〕[month n. 月；-ly →] a. occuring once a month or every month每月的；每月一次的
〔李〕[month n. 月；-ly →] a. occuring once a month or every month每月的；每月一次的